Ceramic Dictionary

by Susan Mussi

ca: BALANÇA

es: BALANZA

Click on the title to see more images

A Balance is an instrument for determining weight using suspended scales. It consists of a bar with a fulcrum in the center and at each end a scale hook or pan is suspended, one holding the object to be weighed and the other holding an object or weights. When weights are the same on both sides the point or support falls into place and is shown as a straight line or 90º. The following photos show two types of balances to weigh different material of different proportions.

The last balance has a rigid horizontal beam supported at its center, with weighing plates hung at both ends and perfectly balanced. A weight is put on one side, the substance being weighed on the other and when the beam is level, the amount is correct. This balance is used for measuring small quantities of up to 10g.
Read more about: Bean scales / Spring scales

ca: ARGILA DE BOLES

es: ARCILLA DE BOLAS

Ball Clay is mixed with many types of clay to build up their bonding and working properties, to increase their plasticity and strength. It is called ball clay because when originally made it was formed in the shape of a ball. When fired it becomes a greyish white color.
Found in Devon and Dorset in England and also in Kentucky in USA, where it is known as Kentucky ball clay.

ca: MOLÍ DE BOLES

es: MOLINO DE BOLAS

Ball Mill is used for finely grinding and mixing colors with clay and pigments with glazes. It is a steel horizontal drum, supported by legs, with a door at the side and a small motor that rotates it at one end. The inside is lined with a strong material and contains loose pebbles or manufactured balls, so when the mill turns the pebbles fall to the bottom of the curve and grind down the materials. The cascading effect reduces the materials to a fine powder and mixes them. Different materials are used for grinding, including ceramic balls, pebbles and flint.

ca: EINES DE BAMBÚ

es: HERRAMIENTAS DE BAMBÚ

Bamboo tools in the first photo they have sharp points and a great variety of beveled edges with a smooth finish. The second is modeling tool and they are all ideal for hand-building projects as it help get to the difficult places to reach. The strength of bamboo allows the tools to be very strong, delicately shaped with a smooth surface.

ca: TÈCNICA-BAMBÚ

es: MÉTODO-BAMBÚ

Bamboo ware started in China in 1600, when they invented a method to make real bamboo flat and pliable so it could be woven and it was and still is used to make vases, trays, etc. European potters in the 17th and 18th century started to copy its texture in pottery and the surfaces of objects were molded and painted to give the idea of woven bamboo.

ca: BANDA

es: BANDA

Click on the title to see more images

Band refers to lines of different widths marked around circular ceramic utensils, plates, jars or lids so both ends meet exactly. Any method, such as painting, drawing, scratching etc. can be used and it can be done at all stages: freshly thrown work, leather dry, bisque, unfired glaze-base, as well as on a glazed surface.

ca: BANDES (a) Procés de treball

es: BANDAS (a) Proceso de trabajo

This section explains how to band and it applies to the different ways of working that follow

The Working Process
1) Place the object you are decorating in the center of the hand wheel, making sure it is centered exactly. If it is not centered properly, the two ends of the line you paint around the circumference, while turning the wheel, will not meet.

2) You can band with a pencil, a paintbrush with water or directly with paint.

3) Draw the banding lines. Balance your right hand on the metal banding bar, holding a soft lead pencil between the fingers of your right hand and just touching what you are decorating in the place you want to start. Using your left hand, turn the wheel by its neck. Do not move your right hand; keep it steady, as the wheel turns, you will draw your line. Using a pencil is a way of provisionally making the lines, which can be used as guides for marking on the designs or for painting the lines.

4) You can paint the lines in the same way directly with a paintbrush and a color or with water.
Water is used when the glaze-base is very dry, doing this helps the paintbrush to move smoothly and not take off the base.

5) Your brush can run out of color, add more to it and continue and if the density of the color varies paint that part again.

ca: BANDES (b) Barres

es: BANDAS (b) Barra

Banding Bars are to support your hand while drawing or painting lines round jars, plates or lids. It should be made of a strong metal, be high enough to decorate the largest pieces you work with and should not move with the pressure of working. The bottom end has a clamp so it can be attached tightly to the edge of a table.

When banding on top of an object, like a plate or a lid, you should stand, and when working round the object, one can sit or stand.
Turn the wheel with your left hand, with the right hold the bar with your little finger and the brush between your thumb and first finger and continue as explained in the working section.
Read more about: Banding (f) Wheel. Explains a wheel that is designed to use with a banding bar. Centering – Banding

ca: BANDES (c) Amb caballet

es: BANDAS (c) Con caballete

Banding with a bridge. To make a bridge, put a bar of wood over two supports. When working on a plate or a lid, the bridge must be the height of the wheel plus the object being decorated, and for jars, it should be the same height as the lines that are to be painted around them. Put the wheel with the plate half way under the bridge, rest your right hand on the wood to steady it and turn the wheel. Put the jar on the wheel, build the bridge up to the height needed and band round the jar.

ca: BANDES (d) A mà

es: BANDAS (d) A mano

Banding by hand. Hold the neck of the wheel with your left hand and the tool with your right one at the required height and rest your arm against the edge of the table, to steady it. Turn the wheel, with the brush touching the pot, until the line has gone right round and joins the starting point.

ca: BANDES (e) Llapis

es: BANDAS (e) Lápiz

Banding with a pencil. Use a soft lead pencil, about 3H, sharpen it and then flatten it on one side by rubbing it backwards and forwards on paper. It is used to provisionally mark the banding lines round objects and the spacing’s for sections of a design that is repeated. As the lead is soft and flat it should not damage the base and lead when fired burns away. These lines are then followed using a paintbrush with a color. They are also used to draw lines onto tiles.
Read more about: Line – Drawing

ca: BANDES (f) Amb torn de sobre taula

es: BANDAS (f) Con torno de sobremesa


Banding wheel is a potter’s wheel that is turned by hand and is used for banding. The left hand turns while the right one draws lines round the circumference of plates, jars, etc. It is also used for decorating and sculpture, as it allows you to turn the work without it being touched. The first photo shows the different, indented circumference measurements, which make centering a piece of pottery much easier and the one on the left shows a banding bar attached to a wheel.

Note: I have been told there are electric banding wheels, I have never seen one, and most probably they are privately made. Read more about: Wheel (c) Hand wheel

ca: CARBONAT DE BARI

es: CARBONATO DE BARIO

Barium Carbonate prevents deposition of soluble impurities on the surface of ceramic bodies when at approximately 2%. In glazes it is a powerful flux at earthenware and stoneware temperatures (10%). In excess it can produce a semi-matt finish and with boron compounds a glossy finish.

ca: BARRES (1)

es: BARRAS (1)

Bars can be round, rectangular, square, narrow and of any length. Made with different materials; wood, metal, chocolate etc. The following sections show two ways in which they are used and through the links many more are explained.

Read more about: Banding (b) Bars / Hand Pole / Line – Drawing / Mold: 4 Made with bars of wood

ca: BARRES (2) Metall

es: BARRAS (2) Metal

Click on the title to see more images


Metal bars; you need several that are long and flat. Used to draw long straight lines, hold tiles in place while screen printing (b) and to straighten when putting them in the cranks for firing, when they are long, drill a hole in one end so they can be hung up.

a) A metal bar clamped to the table at each end keeps the tiles being printed in place.
b) A metal bar being used to straighten the tiles in the crank.
c) Long metal bars with a hole drill in one end so as to hang them up.

ca: BARRES (3) Suport per rajoles

es: BARRAS (3) Soporte para azulejos


Bar tile support is a bar of wood, about 2cm wide that is firmly attached along the bottom of the tile stand and supports all the tiles being decorated.
a) Bar – Tile support
Read more about: Tile – Stands

ca: BARRES (4) Suport per esmaltar rajoles

es: BARRAS (4) Soporte para esmaltar azulejos


Bar tile supports are used when pouring, covering tiles with a glaze-base. Make a long narrow rectangle with bars of wood bigger than the diameter of the container you are using. It must be long enough to use as a bridge across the container and narrow enough to let the tiles that are being prepared overlap it width-wise, making it easier to pick them up. Make sure the bar supports are well joined together and completely straight. As tiles vary in size from 7,5cm (3 in) to 30cm (12 in) wide, two or three different widths are needed. It is also convenient to have 2 separate bars, in case you have to prepare or use narrower or wider objects, like a sieve, etc. Read more about: Glaze-base (e) Applying by pouring on to tiles

ca: BASE - El cos dels esmalts i colors

es: BASE - El cuerpo de los esmaltes y colores

Base: the different ingredients mixed together to form a substance that becomes the body for glazes and colors. Read more about: Glaze-base

ca: BASE – Part inferior d´un objecte

es: BASE - Parte inferior del objeto

Base: is the underneath part of object. In pottery it can be of various shapes, flat, round or pointed. The footing is a protruding ring, which the object stands on. It can be made, when being turned on the wheel as part of it or added. If a base is pointed a separate footing in metal or wood has to be made.

ca: GIBRELL

es: BARREÑO

a) Basin; used for washing hands and faces It is a half circular bowl, made with a ceramic or metal material. They are attached to a wall or table, with taps, drain and made to hold water. Also known as hand-basins and if large and used to clean objects and known as sinks.

b) Basin, made to hold and carry products. Made of china, plastic or metal and are circular containers, with a flat floor. Made in many sizes and with or without handles on the sides. Used to carry and store loose products such and liquids, grain etc. When they have a curved base they are known as bowls

Read more about: Container – Glaze-base

ca: PAL

es: PALO

Bats are flat, rectangular pieces of wood with a handle that can be with or without indented textures. Used to hit clay to flatten it out and leave textures.
Note: Bat has several different meanings in ceramics and the following links are four different way of using it.

Read more about: Beater: tectures / Hammer / Paddle: beating pots / Wheel (f) Bat for throwing

ca: FORN - Lletadaes

es: HORNO - Lechada

Bat wash is a coating of refractory powder made up of half flint and half kaolin that is mixed with water and painted on kiln shelves to prevent wear and the accidental running of glazes from fusing to the shelves.

ca: RECEPTA

es: RECETA

Batch is an amount of raw materials mixed in their correct proportions and prepared for fusion into a glaze.

ca: PLAQUES – FORNS

es: PLACAS – HORNOS

Bats are all type of kiln shelves. Read more about: Kiln – Furniture / Kiln – Shelves

ca: BOLES PETITES

es: BOLITAS

Click on the title to see more images

Beads can be made of different products, valuable stones, metal, wood or anything round you can bore a hole through. Ceramic beads have been developed through thousands of years and have been used in many different ways, body decoration and methods for calculating and also for religious prayers. They are made in clay, fired and decorated using different methods. A bead is usually round, but can be any shape on the outside and always has a hole through the middle big enough to pass a cord through the center, so it can be hung up.

Photographs lent by Caren Shiloh

The first shows 18th century beads decorated with the Majolica method and the last two, forming them in clay.

ca: SEPARACIÓ

es: SEPARACIÓN

Beading is when a fired glaze does not adhere to the surface to which it is applied. It separates, shrinks and rolls back leaving patches showing the bisque body. It can be seen round the edges, in small individual patches or all over the surface. Before the firing the decorated piece seemed perfect.

ca: TASSA

es: TAZÓN

Beaker is a large, straight, high-sided cup used for drinking. It can be with or without a handle and is also known as a mug.

ca: BALANÇA DE PRECISIÓ

es: BALANZA DE PRECISIÓN

Bean balance scales are to weigh small quantities, from 0.01 grams to about 10 grams and are used mainly for weighing colors. It is a measuring instrument that consists of a horizontal lever with arms of equal length called the beam with a weighing pan suspended from each arm. The object to be weighed is placed in one pan and standard weights in the other until the beam is as close to the equilibrium as possible, it compares weights using the standard weights for balances.
Weights for bean scales are so small that they are sold with a block of wood designed with holes to keep the different size weights separately; this allows you to see straight away if pieces are missing. They vary in size according to the size of scale you use. The photo shows one designed for weighing very small quantities of powders needed in forming many ceramic mixtures. Read more about: Balance / Spring scales

ca: BATRE

es: BATIR

To beat is to hit with a strong pressure using your hand or a tool and can apply to mixing a liquid or flattening clay.

ca: BATEDORA – Elèctrica (per barrejar líquids)

es: BATIDORA - Eléctrica (para mezclar líquidos)

Click on the title to see more images

Electric beaters; can be bought and are similar to those used with food, but are expensive. It is more economical to buy the arm designed for mixing liquids that can be attached and used with an electrical drill; this is shown in the first four photos (a–d). They are made with different lengths and head sizes to take into account the depth and heaviness of the liquid. Used for mixing colors, glaze-bases, etc. and are very good when a product has become dry and hard; first cover it with water, leave it for a short period and then beat it.

Both (e and f) are large electrically run beaters designed for mixing new and used clay with water to make a slip. They are put into the big container which holds the slip and are turned on at intervals to mix it and keep it at the correct intensity for filling molds, the arm that holds the beater can be moved horizontally and vertically. When the slip is being used to fill molds, a tube is put in the container that is connected to a compressor. This pulls the slip out into another tube which is connected to a slip gun. With the pressure of the electricity the slip is drawn up and out through the gun and can fill up many molds.

Read more about: Container – Glaze-base / Containers for slip / Drill

ca: BATEDORA- Líquids

es: BATIDOR - Líquidos

Beater: It is a metal tool with a long thin and strong handle, with an oval head made of wires. They are used in cooking for beating eggs, etc. Different sizes can be purchased. Very large ones are used for mixing glazes and other liquid products.

ca: MAÇA - Textures

es: MAZA - Texturas

Beaters and bats are different objects used to indent textures into a soft clay surface. The result is similar to impressed decoration but less planned, more spontaneous. It can be done with string, a butter pat, a meat hammer, in fact anything with rough surfaces, onto a prepared clay object or onto a separated piece of clay, which is then luted and attached to another piece. When glazed, the textures reflect the light and this accentuates the uneven surface.

ca: IMPRESSIÓ - Decoració

es: IMPRESIÓN - Decoración

Beating decoration; shows designs and textures impressed into clay. The decoration can be indented directly into a piece or in a separate piece and then luted on. If luted on, different colored clays can be used.

ca: COLPEJAR FORMES (modelar)

es: GOLPEAR FORMAS (modelar)

Beating forms is to beat clay when it is soft to form a shape, to change a shape, for leveling and thinning a work. It is often used on coiling to level it out, forming very thin, strong walls. This is also known as paddling.
Read more about: Paddle

ca: BENTONITA

es: BENTONITA

Bentonite is clay of volcanic origin, used to improve the working qualities of bodies (up to 5%). It also increases mechanical strength. At stoneware temperatures it fuses to produce an iron brown color (5%).
In ceramics its plasticity helps the suspension of the glaze.

ca: BISELL

es: BISEL

Bevel: It is also known as Bevel Square and is an adjustable tool for marking out dovetails and joints with angles greater or smaller than 90 degrees.
It is useful in ceramics if you have to mark tiles before cutting them down to unusual sizes.

ca: BICOLOR

es: BICOLOR

Click on the title to see more images

Bicolor is the name given to a style of decorating ceramics only with two colors and any can be used, the most classic being manganese and copper green. The plate on the left is copied from a photo; the original is in the Ceramic Museum of Barcelona. It was painted after 1400 AD in Paterna, a town in Valencia. The next two are new ones, which are done using and mixing designs from the past.
Tricolor also exists using three colors.

ca: AGLUTINANT

es: AGLUTINANTE

Binder is a liquid added to coloring pigments to harden and aid adhesion especially when applied to a fired glaze. Arab glue can be also used; it is a natural product that burns away when fired.

ca: TALLADORS DE PASTES

es: CORTADORES DE PASTAS

Biscuit cutters are thin metal walls forming many different shapes and are made for cutting shapes out of pastry to make biscuits. They are used to cut clay in the same way.

ca: BESCUIT

es: BIZCOCHO

Click on the title to see more images

Bisque is the name given to all types of clay which have been fired without a glaze. The lower the temperature of firing, the greater the porosity the piece has as it burns away all carbonaceous matter. The temperature for firing clay into bisque is between 650° C and 1050° C. Refractory can be fired up to 1300° C. The higher the temperature of firing, the less porosity and the stronger it becomes but it is still absorbent to liquids. When you use products in the bisque state that have been industrially made or handmade they can vary in porosity so the drying time of a glaze-base can differ.

Tiles can be bought from the same firm, but each size may be made using a different method and this varies the drying times. The glaze-base on a bisque tile 15×15cm can take up to 12 hours to dry and on one 7.5 × 20cm only 3 hours. This is not related to size but to the methods and products used to make them.

The advantages of bisque firing:
1) The work becomes stronger, less likely to break and easier to handle.
2) Pieces can be piled up on top of each other and stored indefinitely.
3) If broken and the cracks can be seen or heard, they can be thrown away, so time is not wasted decorating them.
4) Sometimes cracks cannot be seen, so sounding the piece before decorating is important, to check that it is not cracked.
5) A flat sound can mean that the bisque has been under-fired or is broken.
6) When you buy clay, you must check to what temperature it can and should be fired. Over-firing clay may turn it into a liquid and destroy your kiln.
7) Clay while being fired shrinks. If you fire clay to its correct temperature, shrinking will stop, but if you under-fire it, when fired again, shrinking will continue.

ca: BESCUIT (a) Preparació rajoles per utilitzar

es: BIZCOCHO (a) Preparación de azulejos para utilizar

Bisque is the name given to all types of clay bodies that have been fired but are porous and unglazed. Always test ware to make sure it is not damaged or broken. Holding it with your left hand, tap it in several places with the knuckle of the first finger of your right hand. If the resulting sound has a high tone, this means that the tile is not broken. If the sound is flat, this means that the tile is cracked. Work can be tested in the same way if it is bisque, bisque prepared with an unfired glaze, or with a fired glaze.

Cleaning: before applying the glaze-base to bisque it must be sand-papered, cleaned by brushing.
If you are decorating hand-made bisque objects made from red clay, dampen them before applying the glaze-base. I always do this but it is not absolutely necessary; it helps eliminate air holes and makes the base run on cleaner and smoother. Quickly dip the bisque into clean water, so every part gets covered, take it out and let it sit for a short while before applying the glaze-base. Only wet handmade objects made in red clay, not white or industrially made clays.
STAGES OF WORKING FOR ALL BISQUE
a) Sound-test work for breakages.
b) Sandpaper and even out any rough surfaces.
c) Clean it by brushing it, inside and out, back, sides and edges.
Read more about: Glaze-base (c) Preparing the glaze-base

ca: BESCUIT (b) So de rajoles

es: BIZCOCHO (b) Sonido de azulejos

Tiles: if a tile is visibly cracked break it, holding it with both hands and forcing it downward. You might not be able to see the crack, but even so, if the sound is flat, it is advisable not to use this piece, as it could break from the heat of firing. If you are not sure it is broken, put it at the bottom of the kiln during firing, so that if it breaks there is nothing underneath it can fall on and damage. Use it for a one tils design, the replacement of one tile in a large design is too complicated to risk.

When tiles have been cut to a special size or for a border, I do not test them, as the sound changes and I assume that with the pressure used by the cutting machine, they would have broken if they were cracked.

Sounding Tiles: balance it on top of the fingers of your left hand and tap in different places, with the first knuckle of your right hand.

Remember: if the resulting sound has a high tone, this means that the tile is not broken. If the sound is flat, it means that the tile is cracked and should not be used.

ca: BESCUIT (c) So de plats, gerres i tapes

es: BIZCOCHO (c) Sonido platos, jarras y tapas


Sounding
Plate: Balance it on top of the fingers of your left hand and tap around the edge with the first knuckle of your right hand.

Jars: Hold it with the fingers of your left hand inside the neck and tap it with the first knuckle of your right hand.

Lids: Hold the flange of the lid by putting the fingers of your left hand inside it, pushing them firmly against the edge. Then tap the lid with the first knuckle of your right hand.

Remember: if the resulting sound has a high tone, this means that the it is not broken. If the sound is flat, it means it is cracked and should not be used.

ca: BESCUIT (d) Neteja de plats, gerros i tapes

es: BIZCOCHO (d) Limpieza de platos, jarros y tapas

To clean, plates, jars and lids that are hand or industrially made, dust or brush them. With handmade pieces, sandpaper any rough parts and if the plates have holes so they can be hung up, check that they are big enough and not blocked, this is explained in drilling holes.

Clean them out with a sharp, thin piece of metal or an electric drill. If the holes are too small, start with a very fine drill, and then use a larger one. Continue doing this, using a bigger drill until the holes are of the required size. Doing it this way makes it less likely to break. The holes should be made before the clay is fired but if there are no holes, start by indenting a small space in the bisque using a nail or a sharp instrument, like a diamond cutter; just enough to stop the drill from slipping.

Read more about: Borders (3) Plate structure / Borders (4) Plate Designing / Borders (5) Plate spacing designs / Borders (6) Plate painting
Read more about: Majolica: 5e – Preparing plates to paint / Majolica: 5f – Twelve plates painted

ca: BESCUIT – Tall

es: BIZCOCHO - Corte

Bisque cutting: if the piece is shaped like a pot or plate it is impossible to cut, as the pressure of cutting through its different densities and shapes will break it. Cutting flat pieces of bisque, like tiles, can be done using a tile cutter and there are two ways of doing so; by hand and by using an electric cutter. The electric cutter can also be used to even off rough parts and round off corners.
Read more about: Tile – Hand Cutter / Tile – Electric Cutter.

ca: BESCUIT – Humitejat

es: BIZCOCHO – Humedecido

Click on the title to see more images

Bisque dampened: if you are decorating hand-made bisque objects made from red clay, dampen them before applying the glaze-base. I always do this but it is not absolutely necessary; it helps eliminate air holes and makes the base run on cleaner and smoother. Quickly dip the bisque into clean water, so every part gets covered, take it out and let it sit for a short while before applying the glaze-base. Only dampen handmade objects in red clay, not white or industrially made ware.

When a piece of bisque has many air holes, dip or brush it with water, before applying the glaze-base. This avoids air bubbles, takes off the dust and helps the glaze to run over it evenly. With normal industrial tiles damping is not needed, as the bisque is compact and fine.

Remember that bisque made by different firms can react in different ways, so before starting a large job, always test them. The photo below shows an industrial tile 24 × 24 cm. The bisque had a rough texture, full of small holes. To help eliminate some of them we previously wetted the part that was going to be decorated with a large soft brush and clean water. When covered with the glaze-base this blocked some of the holes and when fired the few that were left gave it an antique texture.

ca: BESCUIT – Llimat

es: BIZCOCHO – Limado

Bisque filing is to sandpaper or file to correct the shape or to smooth off a rough surface. The best instrument to use is a fettling knife made of metal with very strong rough surfaces; one side is rounded and is very good for pieces that are curved. An electric tile cutter can be used for filing down corners and edges of tiles.
Read more about: Tile – Electric Cutter.

ca: PILONS

es: PILONES

Bits in pottery are small pieces of bisque made with different types of clay, shapes and sizes and can be hand or industrially made as shown in “a, b and c”. They are to support, heighten and balance objects when packing kilns. When not being used in firing, they can be made with any material. In screen printing, “game cards e” are used to heighten a screen to a very fine degree.

Note: In the photo above are different bits; “a, b & c” are all industrially made, “d” is handmade, “e” is broken industrial tiles and “f” game cards.
Read more about: Screen printing (4) Setting up a screen

ca: CERÀMICA BIZEN,

es: BIZEN, CERÁMICA

Bizen ware is Japanese pottery named after the village of Imbe in the province known in the past as Bizen. The method started in medieval Japan and is still functioning in the same way today. Because of the clay composition, work is fired slowly over a long period of time. It is very strong, reddish brown in color and with no glaze. The kilns are fired by wood and the pots are stacked with rice, straw and other products and the combustion during firing causes these to form different textures and markings on the finished work.

ca: NEGRE

es: NEGRO

Click on the title to see more images

Black is a complete color. You cannot have a light black, as it would be gray. Originally black was not used in the “Majolica” method, instead a color which looks like black was made up of other dark colors; brown, blue and red. Manganese, which is a very dark brown, was and is used for dark outlines. Black does not have the problems of manganese, but it gives a hard, modern, industrial finish and it is good when a powerful impact is needed, as shown in the following photo of “Piscis”, the name of a block of flats. In the design the outlines are made following the Dry-Cord method, the glaze-base is scraped away and then painted with black.
Read more about: Dry Cord

ca: ÒXID DE COURE NEGRE

es: ÓXIDO DE COBRE NEGRO

Black copper oxide Copper (II) oxide or cupric oxide (CuO) is the higher oxide of copper. As a mineral, it is known as tenorite. It is a black solid with an ionic structure which melts above 1200° C with some loss of oxygen. It can be formed by heating copper in air: 2 Cu + O2 → 2 CuO

ca: BOMBOLLA

es: BURBUJA

Blister is a bubble or lump in a glazed surface that can burst leaving the area it covers damaged and uneven.

ca: FORMACIÓ DE BOMBOLLES

es: FORMACIÓN DE BURBUJAS

Click on the title to see more images

Blistering is caused by gases escaping during firing which cause faults in the process. Many things can cause blistering, over firing, too thick a coating of glaze or a color, inadequately dried clay.

Manganese is a temperamental color and it is impossible to know why when two pieces of work are prepared in the same way and fired at the same time, one will blister while the other is perfect. The color manganese or colors mixed with a high percentage of it often cause this. It forms bubbles and craters; craters are when the bubbles burst.
Blistering is very difficult to repair. Height wise there is no problem, it can be filed down, filled up with a color or glaze-base, then painted and fired but if the line of the profile is affected there is no solution, the lines would have to be made wider and this would completely spoil the work.

ca: INFLOR

es: HINCHAZÓN

Bloating is a defect in clay, caused by the many gases that come out of the clay during firing and can lead to swelling, blisters and holes in the bisque. It is made up of pockets of gas that have developed after the firing has started; the higher the temperature, the more possibility there is of it happening. It can also be due to the trapping of gases that cannot escape, over firing, bad wedging or foreign materials.

ca: BLAU

es: AZUL

Click on the title to see more images

Blue was one of the first colors used in glazes, blue cobalt oxide has been found in Egyptian and Persian ceramics. In Spain, where Majolica ceramic method began in Europe, blue was one of the first colors and used in many different shades, as can be seen on plates, jars, floors and wall tiles.

a) The first photo shows different shades of blue on a tile. The top on the left is purer blue and on the right the same blue but prepared with a little black and the ones underneath are the same but watered down.
b) This photo is to show the immense possibilities there are for painting with one color.
c) Rabbit: decorated in Catalonia in the 17th Century.
d) Saint: decorated in Talavera in the 17th Century. This shows the two main blues. The dress is a turquoise and the border is a dark blue. This light blue was used more in the south of Spain and Portugal.
e) Shopping: decorated in Manises, Valencia, in the 18th Century.

The last three photos are shown with the permission of the Barcelona Ceramic Museum.
Read more about: Museu de Ceràmica de Barcelona.
Read more about: Majolica: 3 – Decorating / Majolica: Colors (f) Painting with one color

ca: MESCLADORA

es: MEZCLADORA

Blunger is a mechanical container with electrically rotated arms or paddles, made to mix certain products with water such as slip. Slip must be well mixed so the water penetrates between all particles. These machines are made in many different types and sizes for industrial use and for the small potter.

ca: BARREJAR ARGILA I AIGUA

es: MEZCLAR ARCILLA Y AGUA

Blunging is to mix clay and other products with water to make slips. It can be done mechanically or by hand, using a metal beater or any other instrument. Clay slurries need a considerable amount of energy to achieve a slip in which water has penetrated well between all particles. When a machine is used the liquid passes through a fine sieve to separate bits that have not dissolved and any other foreign bodies. If done by hand it has to be passed through a sieve.

ca: COLORS BURROSOS

es: COLORES BORROSOS

Blurred colors occur when they bleed and spread into the glaze or into each other, something that can be either considered a fault or used as a decoration. It happens with many colors and depends greatly on the absorbability of the glaze that the colors are mixed with. In the Majolica method, it can be caused by decorating while the base is still too damp; the effect can be seen as a fault or used as a decoration.

ca: FUSTA (a)

es: MADERA (a)

Boards are flat, thin pieces of wood that can be any shape or size and are used in ceramics for many different purposes, for carrying products, to make shelves, to build up walls for molds and to work with clay. These are known as modeling boards, and can be purchased in different sizes and shapes: round, square and rectangular. The following sections show the different ways in which they are used.
Read more about: Wheel bats – handmade

ca: FUSTES (b) Per argila

es: MADERAS (b) Para arcilla

Boards for clay are known as modeling boards, they are wooden and made to work on using clay. They can be purchased in different sizes and shapes: round, square.

ca: FUSTES (c) Murs para motlles

es: MADERAS (c) Muros para moldes

Boards for mold walls: they are bars of wood of different widths, held together with clay and used to build up the outer walls to make molds.
Read more about: Mold: 4 Made with bars of wood

ca: FUSTES (d) Per transportar

es: MADERAS (d) Para transportar

Boards – Ware boards are wooden, can be of any size and are used for carrying tiles, plates, pots and lids. When made for tiles, they should be about 10 cm wide so that the tiles can overlap them on each side, high enough to enable you to slip your fingers underneath to pick up the tile without touching the decoration and long enough to hold five or six units. They are used to move work from one place to another while the base is drying or decorated. Ensure that the boards are the correct length so they can slide into shelf stands.

ca: COS

es: CUERPO

Body is the term used to describe the structural formula of a material. Clay bodies change according to where they are found and are mixed with other materials to produce special qualities.

ca: COLORANTS

es: COLORANTES

Body stains are colors specially prepared to be added to clay bodies to produce clay of different colors. They can be mixed by kneading to create random effects or separate pieces can be used to build up previously planned patterns.

ca: CENDRA D'OSSOS

es: CENIZA DE HUESO

Bone ash (calcinated bone, calcium phosphate) is a body flux made from animal bones and used mainly for producing the translucency in bone china.

ca: CENDRA D'OS – manufactura

es: CENIZA DE HUESO – manufactura

Bone ash makes up about 50% by weight of the final Bone China body recipe. It is produced from animal bone, which is first processed to remove any adhering meat which is generally sold as pet food. The bone is then treated to remove glue, which is processed and upgraded for use in applications where glue is used, and also for the sizing of expensive paper. The remaining raw bone is then heated to over 1000 C to burn off any residual organic material and change the structure of the bone to a form suitable for the manufacture of bone china. The high temperature used also sterilises the bone. The bone is ground with water to a fine particle size before inclusion in the bone china body.

Real bone ash chemistry
The typical analysis of calcined bone is 67-85% calcium phosphate, 3-10% calcium carbonate, 2-3% magnesium phosphate, and small amounts of CaO and CaF2. However this can vary significantly depending on the source of bones and the process used. The approximate formula is 4Ca3 (P04)2.CaO.
Although raw bone is chemically Ca3 (OH) (PO4)3 hydroxyapatite many authors ignore the hydroxyl group as they believed it is removed on calcination?

Real bone ash chemistry in bone china
On firing as a constituent of a bone china body the bone ash works in a complex manner. The free lime reacts with the stone (type of feldspar mineral) to produce Anorthite (Ca feldspar crystal), whilst the phosphate produces a complex glass and leaving a high level of residual crystal Beta tri-calcium phosphate Ca3 (PO4)2. It is considered that English bone china contains 70% crystals (mix of phosphate and silicate crystals) and 30% glassy material.

Bone ash substitutes
Bone ash and calcium phosphate are both used almost interchangeably in the market although bone ash is a relatively crude product and calcium phosphate relatively pure. The properties of Ca3(PO4)2 and bone ash are however quite different. Bone ash retains its cellular structure even after calcination. Direct substitution of one grade for another is not always easy. For example the replacement of real bone ash by the synthetic bone 1 creates several problems. These include colour, chemistry reformulation and processing issues.

A number of potential substitutes exist for bone ash used in ceramic bodies as follows:-

Tricalcium phosphate-mineral route
Phosphate rock in the form of apatite (Ca5 (PO4)3(OH,F) can be calcined to produce principally tricalcium phosphate Ca3(PO4)2 synthetic bone (1)

Tricalcium phosphate-chemical route
Tri calcium phosphate Ca3(PO4)2 can be produced by a costly chemical route by reaction of phosphoric acid with lime solution.-synthetic bone (2)

Dicalcium phosphate-mineral route
Phosphate rock in the form of apatite (Ca5 (PO4)3(OH, F) can be used to produce Dicalcium phosphates in both the anhydrous and hydrated form. Although chemically similar these are not the same as bone ash but are often marketing as synthetic bone. –synthetic bone 3 and 4
Dicalciumphosphate (CaHPO4.2H2O) and CaHPO4 (anhydrous) are chemicals produced through precipitation from phosphate rock which are demineralised first by
a)sulphuric acid dissolution and then precipitated by CaCO3
b) hydrochloric acid treatment and then precipitated by a saturated lime solution Ca(OH)2.

Dicalcium phosphate-bone route
Processing of animal bone to dicalcium phosphate CaHPO4 (anhydrous) by chemical processing can produce a synthetic bone ash 5 as follows:-
Dicalciumphosphate (CaHPO4.) (anhydrous) is produced through precipitation from degreased bones which are demineralised by hydrochloric acid treatment and precipitated by a saturated lime solution Ca(OH)2.

Author – Ivan Wozniak


Note: Use in ceramics.
Now-days the product used is synthetic and it is part of the tricalcium phosphate in glazes. It is considered a material for high melting temperature (calcium content) due to its phosphorus content which is glass-forming.

ca: PORCELLANA D'OSSOS

es: PORCELANA DE HUESOS

Bone china is a mixture of hard-paste porcelain plus bone-ash (Calcium Phosphate). Bone China was invented in England in the 18th century.
Note: A composition of approximately 25% caolin, 25% feldspar and 50% bone ash.

ca: SEC DEL TOT

es: SECO COMPLETAMENTE

Bone dry is when the clay is dry beyond its natural state, which is controlled by the temperature of the surrounding air. To arrive at this state, it must be fired to over 100º C, the boiling point of water and then continue until the temperature reaches 600º C, when the clay changes to become bisque.

ca: BÒRAX

es: BÓRAX

Borax also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. It is usually a white powder consisting of soft colorless crystals that dissolve easily in water and is a component of glass, pottery, ceramics and glazes.

ca: SANEFA I CANTONADES

es: CENEFA Y ESQUINAS

Border is the decoration that goes round the edge of an object. With plates, jars and lids the border is always part of the piece but with work in relief and tiles it can be part of it or completely separated. In the following sections on borders, all types are covered.

Borders (1) In relief / Borders (2) In relief / Borders (3) Plate structure / Borders (4) Plate designing / Borders (5) Plate painting / Borders (6) On tiles.

Bisque border tiles can be bought but are difficult to find so you have to cut tiles 15×15, 15×20 and 20×20 cm in half for borders and in quarters for corners. They are used in architectural decorating, for framing mirrors and pictures made on tiles.

Note: While painting a picture on tiles, a line of borders must be put on the stand between the tiles being painted and the small shelf they stand on, to protect them from products being used which could damage them. If these fall, they collect on top of the bar against the border and do not touch and damage the prepared tiles.
Read more about: Architectural Ceramics / Tile – Cutter electric / Tile – Stands

ca: SANEFES (1) En relleu

es: CENEFAS (1) En relieve

Click on the title to see more images

Borders shown in relief: If a large quantity has to be made, it is better to use a mold. The following is just to give you an idea for a quick and simple solution. Remember the mold must be bigger than the finished work, to allow the shrinking of clay during drying and firing.

The photographs show part of a tile design for a “patio” restored.
The main tiles are 15×15cm placed diagonally, and the top, bottom and side tiles that are decorated are half a tile 7.5×15cm and are placed vertically and horizontally. The design was marked onto the tiles using carbon paper and the spaces filled up with colors straight onto the bisque, leaving the tile as the background.
a) The photo shows the top border in relief. b) A drawing of (a) as it is difficult to see the shape in the photo.
c) The whole design that is repeated right round the patio.

ca: SANEFES (2) En relleu

es: CENEFAS (2) En relieve

The following shows you how to make and use a simple mold.


The following shows you how to make and use a simple mold.

Shape b): a thin, strong piece of wood cut to the size needed with the shape of the border cut out. There must be sufficient wood at the sides and top and it should be strong enough for the clay to be scraped off.
Width: b) plus the two side walls a).
Length: it can be any length, but is usually made to cut three borders.
Walls a): two pairs, the first should be the exact length of the border being made. They must be high enough to hold b) while scraping off the clay and must be wide enough for a metal clamp c) to hold them in place, on top of the table f). The second pair should be the same height and width as the first one, but longer.
Floor e): it can be longer than the walls. Put the four walls parallel to each other along the edges of the floor and fix them firmly to it with glue or nails.
Bar of wood d): cut to the same width as the space but longer, which makes it easier to pick up and pull out the borders.


Working sequence
1) Roll the clay out into a large, solid cylinder, twice the height and slightly bigger than the border you are going to make. Lay it between two guide bars, half the height of the cylinder and cut it in half length-wise with a clay wire cutter. Open and separate the two halves and lay them flat side down on the bars of wood d), and put one between the two walls.
2) Put the the piece of wood b) with the shape cut out at one end between the two walls and pull it along the top of the clay. You will have to do this several times until all the excess clay is cleaned off and the shape is formed.
3) Pull out the bar d) with the clay, so it just juts out beyond the end of the walls. Hold a wire clay cutter against the outside end of the small walls and pull it down and through the clay. This will cut the border at 90º.
4) Do the same through the space where the walls are separated, which is the length of the border. Pull out the wood and continue cutting at the correct length.
5) Once cut, take out the bar of wood d) with the borders on it. If you have many bars of wood, leave the clay on them until dry enough to be picked up without deforming the shape and then clean them.
6) On a wooden board covered with a cloth, lay the borders out to dry. Put a plank of wood on top to stop them from warping while drying.

ca: SANEFES (3) Estructura en plats

es: CENEFAS (3) Estructura en platos

Click on the title to see more images

Plate borders; borders are spaces that go round the outer edge of an object. With plates the word is used when describing a design or part of its structure. In the structure of plates the border is at a higher level than the center and can be any size, straight or slanted. The photos show four plates, the first two do not have a structural border and the last two do.

The photos show four plates, the first two do not have a structural border and the last two do. They are to show how they can be mixed; “a” decorated border on a flat plate, “b” is a flat plate without a decorated border, “c” a structural border covered by one design, “d” a structural border with a border design.

ca: SANEFES (4) Disseny de Plats

es: CENEFAS (4) Diseño de Platos

The center circumference of the border is narrower than the outer circumference. This must be taken into account by making the design narrower at the inner edge; both lines must follow the curve of the plate. Cut a piece of transparent paper so it is the same shape as the part it has to cover. Mark on the design and the center line and pounce the basic outlines. With any plate, jar, or lid that curves, either inwards or outwards, the transparent paper must be darted or cut so the size can be decreased or increased by overlapping or separating; this helps the paper to fit round the curves.

The plate has been prepared and marked with a pencil line in the following places

a) The top center on the front of the plate is marked. This is so you remember to decorate the design the right way up.
b) The banding lines.
c) The border spacing.

You must calculate and make your design so it fits into the border height-wise as many times as it will be repeated, so it fits in exactly. Here I am going to explain one design used eight times. Mark on the border with vegetable-ash starting at the top; turn the wheel so the center top is near to you. By marking here, you avoid working over the plate and damaging it.

Lay the transparent paper so its center coincides with the line on the plate and it is between the first two banded pencil lines. Mark the first design; turn the wheel and mark the one opposite, next mark the two at 90° on the right and the left then continue filling in the spaces between each one.

If the plates you are working with are made from molds there is no trouble fitting in the designs, but if made by hand you may have to adjust to size and spacing, as they are never exactly the same.

ca: SANEFES (5) Espais per els dissenys

es: CENEFES (5) Espacios para diseñarlos

Plate border spacing, the plate has been marked with a pencil line, in the center of the border at the top, the point that falls half way between the two holes on the back and is to orientate the correct marking on of the design.

Start with the plate borders: First calculate how many times you want the design to be repeated, and then prepare the drawings to size. If the design has to be repeated eight times, then the drawing has to occupy ⅛ of the circumference of the border. Starting at the pencil line already marked at the top-center, which should be marked in a different way to distinguish it from the others, mark the eight spaces round the edge, with the same distance between each one. Calipers can be used for spacing. Open them to the size needed, move around the plate, marking the points.


Plate Layout If the plates you use are moulded so each one is the same size, you can make the work quicker and more exact by doing the layout of the design on paper. The layout sets out the spaces needed to fit the repeated designs into the border. There are two basic layouts for spacing borders b) 16, 8, 4 and c) 12, 6 and 3. You need 1 piece of paper for the layout and one that is cut for each size of plate you use-

(a) For the layout, it is easier to use squared paper which should be cut out to be slightly bigger than the plate. Geometrically work out and draw the lines for the spaces needed, the more exact the better. In the layout diagram, above left, the spacing for 16, 8 and 4 is shown but the same paper can be used for the others, just by marking the lines with different colors. Draw squares that are the width of the circumference of the plates you use. Lay this paper on a flat surface and on top lay another piece of paper which has been cut in a circle to fit the size of the plate you are working with. With a ruler, mark the lines on to it, using the layout to correctly place them, then cut out a small triangle at the edge of each line so the inside point falls exactly on the line.

Lay it on top of the plate and with a soft lead pencil, mark the centers of the triangles needed for your design. If the pattern is going to be repeated eight times, mark every other one.

ca: SANEFES (6) Plats pintar

es: CENEFAS (6) Platos pintando

Click on the title to see more images

Borders of plates: the six photos are to show a few of the many possibilities there are for borders. They can be with banding lines of different widths and colors and with designs that are repeated or separate. There are so many, the same one can also be in different sizes, depending on the size of the plates you decorate and as they are all on transparent paper and pounced, this makes recognizing them difficult. You must file each one with a colored photo and the best way to do this is explained in filing borders. These plates are decorated with the Majolica method and in the section “plates” the whole method of working is explained.

Read more about: File (e) Filing plate designs
Read more about: Bisque (c) Sounding plates, jars and lids / Bisque (d) Cleaning plates, jar and lids
Read more about: Majolica: 5e – Preparing plates to paint / Majolica: 5f – Twelve plates painted

ca: SANEFES (7) En rajoles

es: CENEFAS (7) En azulejos

Click on the title to see more images

The following photos show border designs as part of the tile.
Straight lines that go round the outer edge of tiles can be of different widths and colors and can vary from a single line to an elaborate design.
a) A line with a dark color, about 1cm from the edge is painted round the tile and then the space left is filled up with a color.
b) It has a dark line, then two stripes of different colors and each corner turns at 45º and is painted with a green color.
c) A classical design used for plates and separate borders and here it is a part of the tile.
d) The two blue lines are overlapped by the design in certain parts and cut at the corners.
e) A border that is part of the tile but could also be used as a design on a separate border.
f) An elaborate border, which has the same design on the sides, but the top and bottom are different.

ca: SANEFES (8) De rajoles

es: CENEFAS (8) De azulejos

Click on the title to see more images

Border tiles separate.

Border tiles are usually a repeated pattern on separate tiles that are laid horizontally and vertically round a design to form a frame. These can be any size, but normally measure half a tile in width and a corner is usually half a border. Not all sizes can be purchased, so they have to be cut down from tiles double their size. In Europe they are used in interior decoration: bathrooms, doors etc., and for framing tile pictures and mirrors.
The first photo shows three individual designs; each has three pieces, two identical sidepieces and a corner piece. If you look carefully, you can see the lines that divide them. These are known as border tiles. To make them, they have to be cut down, and the method for decorating them is exactly the same as for normal tiles.

ca: AMPOLLA

es: BOTELLA

Bottle: We think of “bottle” as a glass object but you can also have a ceramic bottle. To be classified as a bottle it must have a narrow neck designed to control the volume of liquid as it is emptied. It can be any shape or size.

ca: AMPOLLA PER AIGUA

es: BOTELLA DE AGUA

A bottle for containing water used to add to colors should be of colorless glass, so you can see that the water is clean and there is enough of it, with a narrow neck to prevent it being used to clean brushes.

ca: ARC - Tallador

es: ARCO – Cortador

Bow – Cutter: has this name because it is of the same shape as a bow used by an archer. They are made in metal of different sizes and have a strong wire between both ends, used for slicing off pieces of clay.

Read more about: Molding – Press molding (1)

ca: BOL

es: BOL

Click on the title to see more images

Bowl is a round vessel with sides to hold liquid; it is always open and can be of any size. There are hundreds of shapes, always round but differing in size and used for different purposes. As the photos are not to scale, the diameter and height of each bowl is given. Many bowls such as a salad bowl, fruit bowl, soup bowl, pastry bowl are in everyday use.
The following section shows bowls used to make “Cremat” which is the Catalan for burnt.

ca: BOL Cremat

es: BOL Cremat

Click on the title to see more images

The photos show two bowls for making a “Cremat” which is a very enjoyable Catalan custom and very useful when a party starts to get boring. They always have legs and are sold with cups and a deep serving ladle. The first photo shows cups without handles and with legs and the second two show the opposite, cups without legs with handles that can be hung round the edge of the bowl.

How to make a “Cremat”

Make some black coffee and keep it hot. Pour a bottle of rum into a cooking pot with a spoonful of sugar, a piece of cinnamon, a handful of coffee beans and the peel of half a lemon. Heat it up until it is boiling, then tip it slowly into the “Cremat Bowl” and, with a match, set light to it and keep spooning to keep the flames alive until half the rum has burnt away. Put out the flames, the best way being to cover it with a large tin lid. Finally, add the coffee which is still hot, put it into the cups and drink it. To add the final party touch, sing while you are spooning the flames!

ca: BOL Tornejar

es: BOL Tornear

Bowl is a round vessel with a deep base. It can be of any size and the wall can curve inwards, outwards or be straight. It is one of the most popular and important pieces of pottery, made for decorative and practical purposes.

The clay has been centered and opened by coordinating the rotation of the wheel with the movement of the hands, the left hand inside the bowl and the right outside and using them simultaneously to form the wall of a bowl. This movement is repeated until you have the thickness and shape you require. To finish the bowl, sponge the inside while supporting it on the outside with your left hand, then turn it upside down on the wheel so the footing can be finished.

Bowl throwing a-b-c

a) Turn the wheel, with the fingers of the left hand on the center of the cone and the right hand on top, pressure downwards to start opening.
b) With your thumbs in the center and your fingers on the outside enlarge the opening.
c) Turn the wheel in relation to the movement of your hands and open the bowl outwards.

Bowl throwing d-e-f

d) You turn the wheel with your left hand on the center and you support the outside with your right hand.
e) The position to have your hands in while thinning the clay, the left inside and the right outside with the fingers together supporting the clay.
f) This shows an alternative way to stretch out the clay; the position of the fingers helps to control a larger quantity of clay.

Bowl throwing g-h-i

g) The position of the hands makes the thickness of the clay the same all the way round the wall.
h) The position of the hands when pushing the edges outwards to form the shape.
i) To correct or change the inclination of the bowl.

Bowl throwing j-k-l

j) Move your hands round to make it circular.
k) Using a tool force the base inwards to accentuate the angle.
l) The bowl has been cut in half to show the angles of the wall and the form of the foot.

Many products made on a wheel, depending on their size and shape, can become deformed when being cut to take them off the wheel as the clay is still too soft. If there is any danger of this happening it is better to work on a Wheel Bat, which works as a tray so the piece can be moved and left to become leather hard, which means dry enough to be separated without being damaged so it can be turned and the footing cleaned. As the clay dries it shrinks and this can separate it from the wheel. If not, it has to be sliced off with a cutting wire, which is pulled between the wheel and the bottom of the bowl.

Note: The different sections in throwing; centering, handle, foot, knob etc., are all explained separately under their name but in the special section “Throwing” they are all explained together.
Read more about: Pot lift. it is a very good instrument for moving work; such as bowls.

All the photos in this section have been lent to me from Revistaceramica.

ca: CAIXA

es: CAJA

Boxes: the most common shape for a box is square, but it can be round or any other shape and the bottom of it is always attached to the sides. They can be with or without lids which can be attached or separate.
Read more about: Slab – Building boxes / Slab – Roller slabbing

ca: CONTENIDORS - Per a esmalt brut.

es: CONTENEDORES - Para esmalte sucio

Boxes for dirty glazes: Three boxes, each one has a different color which is the same as the glaze containers, so you know which one is right. They measure about 30×25cms and are to keep all the dirty glaze of each type, which has been brushed and scraped off prepared pieces, this system avoids mixing one glaze-base with another. They can have water added, be cleaned by passing them through a sieve and put back into the container to be used again.

ca: APILAR

es: APILAR

Boxing is packing bowls, cups and jars rim-to-rim and foot-to-foot while drying and when being bisque fired. This can be done when they are cheese-hard. It helps to stop warping while the clay is drying, as it slows down the process.

ca: EINES DE BOIX

es: HERRAMIENTAS DE BOJ

Boxwood tools Boxwood tools are made in many different shapes and sizes to work with clay. The name comes from a tree which was given the name “Boxtree” when it started to be used to make boxes.

ca: TRENCAR

es: ROMPER

Break is when an object is unexpectedly divided into separate parts or reduced into fragments. It can be caused in ceramics by over-firing, by too rapid a temperature change, by clay not being completely dry, or by it having dried in some parts more than in others.

ca: DESINTEGRACIÓ

es: DESINTEGRACIÓN

Breakdown is the collapse, disintegration and deforming of clay from over-firing. With new or different clay, always check to how high a temperature it can be fired. Clay that is over-fired can spread, like melted chocolate, over the sides and floor of the kiln; this is impossible to clean and all the sections affected will have to be changed.

ca: MAÓ

es: LADRILLO

Brick is a block of clay that has been hardened by drying or fired in a kiln and used for building. It is usually rectangular and when fired becomes red-brown in color.

ca: CERRA

es: CERDA

Bristle is short, stiff, coarse hair used for making brushes. It used to be taken from animals such as pigs, but now it is artificially made.

ca: MARRÓ

es: MARRON

Brown is a color that has been used a great deal in ceramics. It is an earth color and has many different variations when mixed with other colors. We think of it as dark, but it has a range going from a light cream to nearly black.

The following five are ones we use in the Majolica method.

1. Brown – manganese is dark-brown usually mixed with a little red and blue. This tends to give it a purple-brown shade and increases its strength. It is used for outlines and shading with the Majolica method. It is a temperamental color that you have to be careful with, as it burns away. When painting outlines make sure it is strong and be careful as it often blisters.

2. Brown-red came into Spanish ceramics from England during the eighteenth century. It is a reddish brown and warm color, good for shading and outlines.

3. Brown – dirty is a mixture of manganese and ochre. This is called dirty brown, because when in liquid form it has a dirty, muddy color, but when fired, becomes a dark, warm brown. It is not strong and must be applied quite liberally.

4. Brown mixed is 50% brown strong and 50% brown red and used instead of manganese for outlines and shading.

5. Brown-strong is a very dark color, used a lot for shading, over or under another color. When used for shading, it must be well diluted with water and applied thinly.

ca: PINZELL

es: PINCEL

Brush is a tool with a handle and bristles or hair attached at one end by a metal quill. They are made in many different forms, sizes and materials, with different types of bristle from natural animal hairs or industrially made fibers. They have hundreds of different uses, from painting a delicate object to cleaning the chimney.

Over the centuries, brushes have evolved into many varied shapes. They can be made up of many types of hair to produce different brush strokes and textures and to paint using many techniques and products. The following two sections deal with brushes.

ca: PINZELL – Neteja

es: PINCEL - Limpieza

1) Brush cleaning with water. When you finish working, clean your brushes. Glaze colors can be cleaned off with just soap and water. Do not use them for other types of painting and never leave head down in any liquid, as the hairs become bent. With time they can be corrected, but why waste time.

2) Brush cleaning with a solvent. When brushes have been used with a product that has to be cleaned with a solvent, rinse them with soap and water once they are clean. Otherwise they can get spoiled.


3) Brush, soaking: the best way to soak brushes, either in water or in a solvent, is to put all the brushes with their heads together, facing downwards and tied on to a piece of wood or a brush pointed in the opposite direction, allowing the wood to overlap the heads of the brushes. By doing this, you can stand them up on the wood and the bristle will not be damaged or deformed by touching the bottom of the jar and can be left to soak as long as required.

ca: PINZELL - Allargar el pel

es: PINCEL - Alargar el pelo

Brush-hair; lengthening of the hair: if the hairs of a brush get very short and you want to continue using it, you can make them longer in the following way. With a match, heat the ferrule that is the metal band which holds the hairs. When it gets hot, the glue inside will melt and become a molten liquid, then use pliers to pull out the hair slightly. Read more about: Ferrule

ca: PINZELLS – Suports

es: PINCEL - Soportes

1) Brush stand, bisque: this is made in clay and fired. It should be designed to hold all the brushes you need, leaving a space between each one so as to be able to pick them up easily and should have a protruding floor, to catch the paint that drips off.
2) Brush stand, metal: the old fashioned pen stands are very good for this. The two photos on the right show one without and one with brushes, which holds 9 brushes.

ca: PINZELLS – Decoració

es: PINCELES - Decoración

The next photo shows four brushes which are named by the shape of the hair.
a) Flat brush; b) Sumie; c) Fan brush; d) Pointed brush. Paint Brushes.
Over the centuries brushes have evolved into many different shapes, made up of different types of hair to produce different brush strokes, to leave different textures and to paint using different techniques and products. The best is squirrel hair, which is made up in many different shapes and sizes. It is expensive but there is also a large selection of good and more economical brushes to choose from. The hair should not be too long and be able to retain paint, to allow for long, strong, smooth lines, suitable for general decoration. A brush should be soft enough to relate to the movements and intensities you are imposing on it to create lines and curves.

The following gives a list of the names of the different types of hair and fibers and the names of the styles of decorating with which they are used. The photos only show one but many are available in different sizes. Brushes for decorating ceramics are made with many different types of hair and fibers.
a) Mexican White Fiber is a cream-colored hair which is strong and used for slip and making textures.
b) Goat Hair is usually of good quality, held in a quill and wire bound. The hair forms a large, soft body so it can hold large quantities of decorating media. Leaves no brush marks and is used for painting on slips and glazes.
c) Mexican Black Fiber is a strong, black hair.
d) Hog Hair is a strong, cream hair, used for slip and lawn brushes.
e) Ox Hair is strong, brown and resilient. The brushes are wide with sharp corners. They are used for painting over large flat spaces or fine lines using the corner edge of the brush.
f) Pony Hair brushes are usually made in Japan; the hair is strong and wide.
g) Sable Hair. There is a large range of these brushes; they all end in a fine point. The small sizes are good for drawing and detailed work; the larger ones for general decoration of glaze and slips and are useful for on-glaze decoration.
h) Sheep’s Hair brushes usually come from China. They make an excellent pottery brush of long, soft white hair.
Left: Chinese, with sheep’s hair and made with bamboo handles. They are separate brushes of the same size but joined together to make up one brush.
Right: Chinese sheep’s hair brush, bamboo handle and ox horn ferrule.
i) Squirrel Hair brushes are made in many different shapes and sizes. They give a strong, smooth line, suitable for general decoration in both the under-glaze and on-glaze method. A brush with long hair and thin point can retain a large amount of paint, which allows for long unbroken strokes and lines.

ca: PINZELLS – Aprofitables

es: PINCELES - Aprovechables

a) Brush – to clean bisque. Before starting to decorate, you must clean the dust off the bisque. You need a brush that is not too hard or too soft. The most popular ones are wide, short handled and with soft washable hair, used for painting furniture. They are used to clean the dust off all bisque objects before starting to decorate.

b) Brush – to clean glaze-base. Very soft, large brushes, made in China. They are cheap, washable and do not lose hair. When ware has been prepared with a slip or glaze-base and needs to be cleaned of dust or dirt these brushes are excellent as they are so soft and do not scratch or damage the unfired surface.

c) Brush – to clean small parts. This is an old toothbrush with its hair cut down, it is strong and good for cleaning the glaze off the foot of plates and jars.

d & e) Brushes – to clean glaze-base off tiles. This is the type of brush used for scrubbing floors, it should be purchased with natural bristle and wooden body. There are two types (d) is the strongest and (e) has bristles that are thinner and softer. When tiles have been prepared with a glaze-base they are used to clean off the base from their backs and sides. To start use a strong brush, the more you use them, the more they wear out and the better they work. The most worn-out ones are good to clean the backs of tiles, on which there is a lot of glaze-base. To make more work all industrial tiles are made with a protruding design on the back and the more intricate the design the harder it is to clean. Read more about: Glaze-Base (f) Cleaning it off tiles

f) Brush made of palm leaves. This brush has the form shown in the two photos. They are made out of leaves of palm trees and made in different sizes. If the brush is new, soak it in water, the older and more used, the better. Knock it about a bit to give it an uneven texture. It can be used for dusting the bisque and is very good for making uneven textures with glaze and colors.Read more about: Glaze-Base (m) Textures

g) Brush – to paint outlines in the Majolica method. You need two or three brushes, about size 10, cut down to a different thickness to form a narrow, flat end. The thick part holds the paint so it runs down through the thin part and allows long unbroken strokes. The drawing shows a brush before and after cutting, these are for painting outlines.

ca: BOMBOLLES

es: BURBUJAS

Bubbles in the glaze-base. Before starting scoop off all the air bubbles that are floating on the surface. If they are left when the work is covered with the base they break and leave indentations on the surface and have to filled up and leveled out.

ca: GALLEDA

es: BALDE

Buckets are usually made of metal or plastic, they are round, have a strong handle and can be lidless or lidded. If lidded they should have fasteners to keep the lid tightly shut. Tight fitting lids help to keep products clean and stop them drying too quickly. They come in different sizes height-wise and if the lids are straight, can be stacked on top of each other. They can also be used for mixing products, slips, clay and glaze-base.

ca: BEIGE, COLOR PELL GIRADA

es: BEIGE - COLOR PIEL DE ANTE

Buff color is a yellowish brown color and the word comes from the color of a buffalo skin. It is used to describe the color of fired clay that has enough iron to take away its claim to being white yet not enough to make it a brown or red.

ca: CONSTRUINT AMB ARGILA

es: CONSTRUYENDO CON ARCILLA

Building with clay is to create a form by adding on sections of clay together like slabs, coils and as clay in architectural sculpture.
Read more about: Architectural – Sculpture / Coiling – Coil Building / Slab – Building boxes

ca: TAPONAR

es: TAPONAR

Bung is the name for the way of setting up saggars vertically, one on top of the other, into the kiln. Saggars are kiln furniture, round and square, with a floor and can be of different heights and sizes, designed to stand vertically one on top of the other. They are boxes to hold one or many pieces of decorated work and while being fired are held together by wad or coil of clay.

ca: CREMADOR

es: QUEMADOR

Burner is the system through which fuel, combined with air, is fed into the kiln, creating the necessary mixture for combustion.

ca: EXTINGIR

es: EXTINGUIR

Click on the title to see more images

Burning out occurs when a substance in a product being fired has a lower burning point than what it is being fired with and burns away. This can be damaging or used constructively.
In the design shown in the photo below, the outlines were painted with varnish on to tiles in the bisque state. Each space was then filled up with a color. The lines help to keep the colors separated and when fired the varnish burns away leaving the color of the bisque.

Products like vegetable oil, varnish and glues are used to adhere colors on to a base that has already been glaze fired and they act as a binder during decorating.

Rice, petals, etc., can be put with clay or glazes to form patterns once fired. When fired they burn away leaving their shape indented. Read more about: Dry Cord

ca: BRUNYIR

es: BRUÑIR

Burnishing is to rub the surface of the leather-hard clay with a smooth tool to produce a smooth, polished surface. The finer the texture of the clay the more polished the surface can be. The color will depend on the color of the clay. For burnishing any curved tools can be used such as teaspoons, stone, etc. It can be decorated with slip or fired and then decorated in different ways or just covered with a glaze to show the polished surface over the color of the clay.

ca: CREMAT

es: QUEMADO

Burnt is when a product has been overheated and has left a black ash surface.

ca: RECOLLIT DE L'ESMALT

es: RECOGIDO DEL ESMALTE

Butterfly is when part of the glaze lifts up and folds back during firing, leaving a bare space showing the bisque.