DAMP
ca: HUMIT
es: HÚMEDO
Damp: is to be moderately wet; it can affect work in different ways and stages, some damaging, some constructive. Look under the following headings.
See: Bisque Damping / Clay Damping
DAMP BOX OR CUPBOARD
ca: PASTAR AL BUIT – desairejar
es: ARMARIO HÚMEDO
Damp boxes or cupboards: are lined with metal or plastic to retain moisture, which allows the storage of unfinished work in clay for long periods.
DE-AIRING
ca: PASTAR AL BUIT – desairejar
es: AMASAR AL VACIO
De-airing clay is to remove air from clay by passing it through a plug mill. It makes the clay denser and more plastic.
DECAL
ca: CALCOMANIA
es: CALCOMANÍA
Decal is an image or a design printed with ceramic material on a special paper so that it can be transferred onto bisque ware or a glazed surface and fired. It is another name for a transfer. See: Transfers
DECOMPOSITION
ca: DESCOMPOSICIÓ
es: DESCOMPOSICIÓN
Decomposition is the breaking down of chemical compounds during firing.
DECORATION
ca: DECORACIÓ
es: DECORACIÓN
Decoration in pottery is enhancement of pieces in many different ways and at different stages of their development.
Clay: Different colored clays can be intermixed or form patterns; textures and shapes can be added or indented into the clay; slip colors applied in different ways, graffito, slip trailing, etc.
Bisque: The decorating can be done by putting colors directly onto a piece of bisque or covered with opaque glaze-base and then be decorated with colors. In both cases, the many different ways of applying colors can be used, sprays, dry cord, tube lining, etc.
On-glaze: Is to paint over a fired glaze adding designs and colors; screen printing and transfers can be used.
DECORATION - Figurative
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Decoration figurative depicts human and animal figures in painting. They are used to tell stories, from the earliest times of cave paintings to today and show stories, actions and human behavior.
DEFLOCCULATES
ca: DEFLOCULANT
es: DEFLOCULANTE
Deflocculates are chemicals like sodium carbonate or sodium silicate added to slips to increase its fluidity. They are used generally for the fabrication of mold sections to help separating.
DEFORMATION
ca: DEFORMACIÓ
es: DEFORMACIÓN
Deformation the changing of the shape caused by stress or strain of overheating when firing ceramics. The result can be caused by firing temperatures too high, so that the work in the kiln can no longer keep its shape. It can be caused by impure clay or faults in the construction of the work and it is most noticeable in flat objects like tiles. Kilns shelves can bend but the standard of kiln ware is now so good that this seldom occurs; it is more likely to happen, in hand made work.
DEHYDRATION
ca: DESHIDRATACIÓ
es: DESHIDRATACIÓN
Dehydration is the removal of water from chemical compounds, compounds like clay.
DELFT
ca: DELFT
es: DELFT
Delft is a town in Holland that has specialized in pottery using the Majolica method for many centuries and this method is known in and outside Holland under the name of the town. In England it is called English delftware and now through American influence it is becoming known as Majolica. Many countries have their own name for this method but basically the working process is the same; over earthenware an opaque white tin-glazed is laid, then decorated and both are fired together. It is interesting to be able to appreciate the variety of styles which developed from the same method in the European countries. What makes them different are the ways of designing, using colors and the form given by brush strokes.
Catalan – Majólica / Holland – Delft / England – Majolica / France – Faience / Italy – Maiolica/ Spain – Mayólica.
If you want to learn how to work in the Majolica Method of decorating you can do it through this web or buy my digital book in Internet. Link to The Majolica Method
DENSIMETER
ca: DENSÍMETRE
es: DENSÍMETRO
Densimeter is an instrument, like a thermometer, made to measure the density of a liquid substance; this is only necessary if it is important for your work to be uniform in its glaze-base. One of the attractive things about hand-made work consists precisely in the small differences, their non-uniformity. It is mainly used to measure glaze-bases and colors. A thin one gives an antique look, allowing a slight redness of the bisque to show through; a thick one gives a whiter, more industrial texture.
DEVITRIFICATION
ca: DESVITRIFICACIÓ
es: DESVITRIFICACIÓN
Devitrification is the crystallization in glazes which melt during the cooling causing side-effects, such as a matte surface.
DEWATERING
ca: DESHIDRATACIÓ
es: DESHIDRATACIÓN
Dewatering; Clay is made from earth, the earth is made up of water and clay and dewatering is to separate one from the other. It can be laid out in the sun, left on top of an absorbent surface such as brick or wood or passed through a cloth bag. Put the clay on to a piece of square material, which has a large weave to let the water run out, pull up the four corners, tie them together and hang it up over a bucket. In the past, large brick outdoor sieves were use so the water could run back into the ground. A potter tossed and turned until it had the right density, then sieved and made into plastic clay. This is now done by manufacturers and most potters buy prepared clay.
DIAMOND CUTTER
Diamond cutter has this name because it was originally made with a diamond. It has a “T” shape and at the top in the middle there is a stone with a very sharp and strong point. It is used to work on what has been glaze fired to scratch off dirty marks and lumps and to force a small indent, which is useful when drilling holes into glazed work, as it stops the drill from slipping.
See: Drilling Holes
DIE PLATE
es: TROQUEL - Disco
Die plate are small metal disks, round and flat and with different cut out spaces. They are attached to the mouth of clay extruders. Clay is pressed through and comes out as a coil with the outside circumference the shape of the die. It can be cut in slices, laid flat to form a pattern or used for handles, etc. The tools they are used with are known by the names of wad mill, dog box or extruder which is the name mostly used.See: Extruder
DIMPLED GLAZE
ca: PUNT D’AGULLA – en l’esmalt
es: PUNTO DE AGUJA - en el esmalte
Dimpled glaze is a glaze surface with tiny holes that look as if they were produced by pressing the point of a pin into it; these are considered a glaze imperfection which can be caused by firing too quickly. Another cause can be a rough surface of bisque; the glaze sinks into the spaces leaving a dimple or indent.
DINNER SET
ca: VAIXELLA
es: VAJILLA
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Dinner set are all the pieces of china needed for a main meal. Which are made up for 12 people and have two sections, table plates which are different types of plates made for each guest and service plates which are the ones prepared to bring food to the table.
a) Table plates: Dinner plate, Salad plate. b) Soup plate.
c) Serving plates d) Soup tureen, very deep and has a lid.
DIPPING
ca: IMMERSIÓ
es: INMERSIÓN
Dipping is applying a glaze liquid or slip to the body of ware by immersing it into a liquid product.
Inside: Fill up a jug with the liquid, pour it inside what you are decorating, filling it to the top, then tip out the unwanted glaze.
Inside: Fill up a jug with the liquid, pour it inside what you are decorating, filling it to the top, then tip out the unwanted glaze.
Outside: Put your fingers inside the neck of the jar to hold it, dip it into the glaze, so it is immersed up to the top of the outside wall. Lift it out and allow the surplus glaze to run off. Put it to one side and leave it to dry, then clean the foot-ring and sign it and repair any part that is dirty or damaged.
This is the most common way, but method explained in the section “Glaze-bases applying” is much better, the difference is that you hold the ware horizontally not vertically and dip the whole pieces into the glaze-base.
See: Glaze-Bases applying it to tiles / Glaze-Base applying it to plates, jar and lids
Dish is a shallow plate, with the edges gently slanting upwards to stop liquids from running off. It can be thrown, molded or built up. They are usually made with a mold. They are made in different shapes, square, rectangular, etc. using a drop or hump mold.DISK CUTTER OR MARKER
ca: TALLADOR DE DISC O MARCADOR
es: CORTADOR DE DISCO O MARCADOR
Disk cutters or markers are used to cut or mark circles of different diameters onto flat clay and can either be bought or handmade. You need a flat disk of wood, about 6cm in diameter, plus a thin bar of wood. It should be about 2 cm wide, but can be any length and should have holes drilled through it at the distances required.
One end is attached to the centre of the disk so that it can be moved round. Clay is rolled out and the disk is put on top. Push a narrow sharp instrument through the appropriate hole, and by rotating the arm you can cut or mark the circle.
DISPLAY PLATE HOOKER
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Display plate hooker: This was invented by the owner of a ceramic shop in the old part of Barcelona. The room is very large, with high stone walls covered with plates. So as not to have to get out a ladder every time a client wanted to see a plate, he invented.
“THE PLATE HOOKER”.
He has two; they are both the same but have handles of different lengths. The hooks in the walls are permanent and the plate-hooker allows the plates, at all heights, to be taken off and hung up quickly.
How it works
The part that carries the plate is made of thin, strong metal wire. It has an oval shape, wide and deep enough to hold the biggest plates. Plastic bubble wrap is laid round the inside of the hooker to help hold the plate steadily, particularly the smaller ones. All the plates are made with two holes in the flange; string is passed through them so they can be hung up.
The back of the hooker has a piece of metal with an opening in the middle. At the top, on each side of this space, you find a Y-shaped piece of metal. The plate is put into the hooker; the string of the plate is slipped into both Y’s. The hooker is lifted up so that the hook in the wall, where the plate has to hang, goes through space in the metal. The hooker is then moved down until the nail catches the string and your plate is hung up
DISPLAY SHELVES FOR TILES
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Display shelves for tiles: This photo shows the tile shelves in the showroom of our studio, designed to store and exhibit tiles. All the shelves are movable, so the space between them can be changed. There is room for a pile of fifteen tiles behind the one on show. The drawing shows the side view of the shelf.
DISPLAYING
ca: EXPOSAR
es: EXPONER
Displaying is to show, exhibit or make visible. If you deal in ceramics as a business, you must display your work attractively at your studio and in the shops where it is sold, so explain to your clients the best way to do this. If not, tiles and plates will be put one on top of the other, so they cannot be seen and won’t sell!
DISPLAYING TILES
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Displaying tiles of individual designs: The photo shows a wall displaying tiles, where you can see what a large amount can be displayed without taking up a lot of room; this method allows you to take the tiles out and put them back individually.
Wall stand – side view
The space under the bar that goes over the top of the tile must be large enough for the tile to be moved up over the bottom bar. When the tile is in place, the wood at the top overlaps and holds it.
To put in and take out tiles:
Slip the tile up and under the top edge, over the bottom edge and let it down. The size of the space left at the top must be calculated so the tile can be lifted up, out and over the bottom edge. The exact measurement must be calculated so that the part of the bar which overlaps the tile when holding it in place at the bottom and top, is as small as possible, so as not to cut too much of the design.
DISPLAYING TILES AND PLATES
ca: EXPOSITOR DE RAJOLES I PLATS
es: EXPOSITOR DE AZULEJOS Y PLATOS
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Displaying plates: There are many different types of plates in size and shape. Cover the walls with white plywood from side to side and as high as possible. When it is firmly attached, calculate where you want the plates and mark the place, hammer a nail in it at 45º and hang up the plate. This is quick and good because if you have to change the place, you just take out the nail and move it; there is no need for drilling holes, tacks or hooks
Displaying designs of four or more tiles: It is advisable not to mount or frame a tile design; this will depend on the client’s taste and where they want to put it. It is better to build up a tile support. Make a false wood wall to the height needed, give it a slight slant and at the bottom, attach a bar of wood, about 1½cm wide. This is to support the tiles when they are laid out. It must be strong, safe. This can be seen in the bottom half of the photo above.
DISSOLVENT MATERIALS
Dissolvent materials: Substances which burn away when fired, such as rice, leaves and petals, organic stains or natural substances like vegetable-ash, talcum powder; these are used to mark on pounce designs on clay and glazes. Varnish and oil paint are used to adhere and keep colors separated when painting on to an already fired glaze.
DOD BOX
ca: DOD CAIXA - EXTRUSIONADORA
Dod box is a hand-operated tube made with metal or plastic used to make strips of clay. It has discs with cut-out designs, known as dies. The die is put at the bottom of the tube and the clay on top, the handle is pushed down the tube and the clay passes through the die, coming out at the bottom to form a dod, a coil in the shape of the die; these are usually made to form handles on jugs and jars.
Note Dod box, Wad mill or Extruder are different names for the same object and Extruder is the one most commonly used where you will find more information with illustrations.
See: Extruder
DOWNDRAFT KILN
Downdraft kiln is designed so that the heat moves up through the kiln, then down and out through a chimney in the floor at the bottom of the kiln.
DRAFTING TABLE
ca: TAULA DE DIBUIX
es: MESA DE DIBUJO
Drafting table is a drawing board attached to legs. A stool that can be adjusted in height is necessary, so the table can be used standing or sitting and the angle can be altered. There are many types and sizes made to draw the exact lay out of a design from a block of flats to a textile design and have many parts attached to it, to hold pencils, lights, rulers and even computers.
DRAPE MOLD
Drape Mold is a support, a stretched cloth, a wooden frame or rope network on which a clay slab is draped to shape as it stiffens.
DRAWING
ca: DIBUIX
es: DIBUJO
Drawing is using graphic representation or lines to form a design, sketch or plan. In ceramics it is very difficult to define. If you draw onto soft clay it becomes “scraping”. If you draw with colors it is decorating or painting. So I define drawing as a design on paper, the outline of which will be used.
DRAWING BOARD
ca: TAULER DE DIBUIX
Drawing boards were originally different sized planks of wood, usually rectangular, made to hold paper to draw and decorate with pencil and paint. Nowadays there are many different types that are industrially made and have smooth surfaces and rounded corners, warp resistant designed for working outside, with a handle or a cut-out space for carrying and they come with metal clips to hold the paper in place.
They can be supported by an easel, flat on a table or with a drawing board table stand which supports it from behind and can be adjusted to the angle needed for working.
DRAWING BOARD STAND - Portable
ca: TAULER DE DIBUIX – Portàtil
es: TABLERO DE DIBUJO - Portátil
Drawing board table stands are designed so that you can sit while working, they are made in metal or wood to hold a drawing board, some can be set at different angles. Tile table stands, are handmade, they can be moved but not folded, and made to hold up to six tiles (2×3) vertically or horizontally.
DRAWING ON TO BISQUE
Drawing on bisque; there are specially prepared pencils of different colors to draw on to bisque. The drawings have to be covered with glaze before firing. If you draw with a lead pencil or oil paint, these will burn away when fired.
DRAWING ON TO CLAY
Drawings can be marked on to clay in two ways and when marked it can be manipulated, following the outlines.
1) Lay the drawing on top of the clay and using a narrow tool with a rounded head, go over the outlines, indenting them into the clay.
2) Pounce the outlines and mark them on with white talcum power.
Drill: An electric machine designed to make different sized holes into different materials including ceramics. DRILLING HOLES INTO BISQUE OR GLAZED WARE
ca: PERFORACIÓ DE FORATS EN BESCUIT I CERÀMICA ESMALTADA
es: PERFORACIÓN DE AGUJEROS EN BIZCOCHO Y CERÁMICA ESMALTADA
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Drilling holes into bisque or glazed ware; you must use a strong, pointed instrument, like a diamond cutter to scratch or indent a small point where the hole is needed. If what you are working on is flat, lay it on top of a piece of wood. You need four hands, two to hold the tile down and two to drill. Use an ordinary electric drill to make the hole, the indent will stop the drill from slipping and sliding. Start by using a very a narrow drill bit, then change it to the next size and enlarge the hole; go on doing this until it is the right size. Having the wood underneath gives a soft support and allows the drill to go right through, which decreases the pressure and the possibility of the tile breaking. On a hard surface the vibration when the drill touches it could break the tile.
Drilling holes, the best way; When decorating with colors or a glaze-base and the decoration is finished but not fired, take a small instrument like a tooth-pick and make a small space in the glaze-base at the point where you want to drill a hole. When fired, the indent will keep the drill in place. This we do when making sun clocks; the hole is to hold the metal arm that reflects the shade that tells the time.
Plate holes are difficult because the size of the footing is usually narrow and this makes the probability of breaking bigger. It is much better to do it while it is still in the clay state, using a tool know as a hole piercer. If not follow the instruction above for tiles
DRILLING LARGE HOLES
ca: PERFORACIÓ DE FORATS GRANS
es: PERFORACIÓN DE AGUJEROS GRANDES
Drilling large holes in tiles, is needed in order to pass tubes or wires through tiles for taps and or legs of sun shades that have to go through the middle of the table. There are special drill bits for large holes that can be brought in different sizes. It is in one piece a bit with a wall, the wall is the size of the hole you need and is designed to cut out circles. It is attached to an electric drill and when used the bit goes into the tile and as it moves down the wall cuts out the circle.
DRIPPING
ca: DEGOTEIG
es: GOTEO
Dripping: is when a liquid falls in separate sections or drops. In ceramics it is used to describe a method of laying a glaze-base or color onto a ware.
See: Glaze-base textures with colors / Glaze-base textures
DRY CORD
ca: CORDA SECA
es: CUERDA SECA
Dry Cord is the literal translation of the Spanish “Cuerda Seca” It is a method of making the outlines, of a design, at a lower level than the glaze-base or colors and it can be done in two ways. The following three sections show examples of how this method can be used.
The tiles can be bisque or covered with a glaze color or glaze-base. The design has been prepared to the size needed and the outlines pounced. They are then marked onto the tiles with black charcoal – powder if what you are working on is a light color or white industrial talcum powder if it is dark color or bisque.
1) The tiles have been prepared with a glaze-base or color and the outlines marked on. The outlines are then scraped off, when finished brush off any loose particles and round and clean the edges with a soft brush and water. These parts are at a lower level and can be left, so that the color of the bisque is seen or painted with a transparent glaze or a color to accentuate the outlines and the dimensions of the design.
2) On bisque tiles the design is marked on. Then the outlines are painted either with oil paint, which will burn away when fired, leaving the red of the bisque showing, or painted with a dark ceramic color, which will stay. The spaces are then filled with colors or a glaze-base and then decorated.
Tools needed
a) Make a scraper as shown in the drawing. Use a dowel or an old pencil with a thin bit of flat metal, bent in a triangle shape, attached to one end. Its size depends on how big you want the outlines to be.
b) A clean, soft brush to clean off the loose glaze
c) A cup of clean water and a soft brush to smooth the rough edges.
Dry cord – different methods are shown and explained in the following three sections.
DRY CORD 1
ca: CORDA SECA 1
es: CUERDA SECA 1
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LA GARRAFA
Name of a restaurant, overall size 44 tiles 60×165cm, tiles each 15×15cm. Fired at 980º C.
The bisque tiles were prepared with a white opaque glaze base, laid on a flat surface so the outline of the letters could be marked on with charcoal-powder. Following these lines, using a large scraper, the glaze-base, which formed the letters, was scraped off. The edges of the letters were cleaned, taking off the loose glaze with a dry, large, soft brush and then with another brush and clean water, they were smoothed.
The spaces were then refilled by dripping a red glaze into them, leaving a line showing the bisque between the white glaze-base and the red.
The border, which is an integral part of the perimeter of the tiles, was marked on, the whole design was placed on a stand to paint. The outlines round the letters were painted in black to accentuate them and the border in the Majolica method. Finally it was all fired together st 980ºC.
DRY CORD 2
ca: CORDA SECA 2
es: CUERDA SECA 2
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GEMINIS
Overall size 36 tiles, 90 × 90cm. Tiles 15 × 15cm.Fired at 980º C.
Geminis is one of five different names, designed for the entrances of a group of apartment buildings to make each one distinguishable from the road.
The glaze-base has a texture formed by throwing a fine coat of glaze-base over the tiles which is then spattered on top with the same substance but much thicker. To accentuate the design, all the outlines were done in the Dry-Cord method.
The design was marked on with charcoal-powder and the glaze-base was scraped off the perimeter of the letters and the figures, leaving an indent of 1cm. wide showing the bisque. This was then painted with black, after which the rest of the design was painted in the Majolica method.
See: Glaze-base textures
DRY CORD 3
ca: CORDA SECA 3
es: CUERDA SECA 3
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FISHERMEN
The first two photos are designs made for the outside if a building and the last shows one in its architectural setting
The designs have 44 tiles, 20 × 20cm so the whole design 220cm x 80cm, the design was put on to transparent paper and pounced. It was then marked on to the bisque tiles with industrial talcum power. Talcum powder, being white, shows up against the red of the bisque. The outlines of the drawing were painted on with oil paint, and then the spaces were filled up with ceramic oxide colors that vitrify at 1000º C. When fired the oil paint, being a vegetable product, burns away and leaves the color of the bisque as an outline.
Tiles are 20 × 20cm and the whole design 220cm x 80cm, the drawing was made on paper, then pounced and marked directly onto the bisque tiles with industrial talcum power. Talcum powed, being white, shows up against the red of the bisque. The outlines of the drawing were painted with oil paint and the spaces were filled up with ceramic oxide colors that vitrify at 1000º C. When fired the oil paint, being a vegetable product, burns away and leaves the color of the bisque as an outline.
DRY FOOTING
ca: PEU SEC
es: PIE SECO
Dry footing is a potter’s term for removing the glaze from the foot of a plate, jar or lid before firing, as the glaze when fired becomes glue and will adhere to whatever it touches.
DRYING CLAY
Drying Clay is the elimination of water from clay. The insufficient drying of clay before firing can result in a piece exploding in the kiln, while drying too fast and can cause warping or cracking.
DUNTING
ca: FISSURA
es: FISURA
Dunting is the cracking or breaking of pottery inside the kiln, usually after firing and caused by cooling too rapidly. It is caused either by drafts of cold air, which make one part of the pottery contract quicker than the others or by the ware cooling too quickly, causing hairline cracks or fracturing ware into many pieces. It can be caused by many things, including different thicknesses of clay in the same body. This happens more with thick clay because the outside can be dry but the inside still damp, so when being fired, the gases and heat cannot escape and the force breaks the work.
DUST
ca: POLS
es: POLVO
Dust is powder made up of thousands of fine dry particles of earth or other matter that is carried by wind and drafts and forms in layers over static objects. In ceramics there are many material that are supplied in powder form and great care should be taken when using these products as they are made up of very small particles that are suspended in air. Goggles and mouth masks should be used when working with them.
DUSTING
a) Dusting is to shake a product in powder form through a sieve over whatever you are decorating. It is usually performed over damp clay, as this will absorb and hold the powder, but it can be done over bisque with dry colors and glazes. It is very delicate, so be very careful when moving it and keep it away from drafts.
b) Dusting is to clean by rubbing a dry cloth or soft brush over a surface that is dry but covered with a layer of dust