SCREEN PRINTING - In pottery (0) The ways of working.
ca: SERIGRAFIA - En Ceràmica (0) Tècniques d'impressió.
es: SERIGRAFIA - En cerámica (0) Técnicas de impresión.
To print with a screen is to transfer a color through a stretched material on a frame, screen printing is always done onto flat surfaces. The colors pass through the screen by dragging them with a squeegee across what is being decorated, leaving a flat printed pattern. You can print on different materials: cloth, plastic, silk, etc. Here we cover the methods used in ceramics.
Direct printing:
Over clay. Printing onto clay is only necessary if you have to shape the piece, or to reduce the process to a single firing, especially at high temperatures. The surfaces must be flat in both cases.
Over bisque: To print on to bisque it is easy because the surface is very absorbent, so the color when it passes through the mesh dries almost instantly.
Over a crude glaze: Work that has been bisque fired is applied with an opaque glaze by dipping or throwing. It is then decorated with colors prepared with a transparent glaze the two are fired together at 980º C.
Over a fired glaze: Silkscreen printing is commonly used on glazed pieces which are non-absorbent. It is usually done at a low temperature and is particularly suitable for the third firing with pigments that vitrify between 750 and 800° C. The pieces for screen printing in this case must dry quickly.
Note: To screen print with the Majolica method, only the outlines should be printed. The colors are painted by hand, which is very important for the end result. Two colors which overlap create a different one and the brush strokes give shape and volume and can be used with different intensities, all of which is impossible in screen printing.
Indirect printing: printing a transfer
With this system, you can print ceramic transfers. The image is printed on emulsified paper which is soaked in water before being applied to a piece of pottery. The working method of preparation comes from the graphic arts. The colors used are called enamels and the temperature is controlled by the amount of flux in the composition of the color, the more flux the lower the temperature. The fusion is between 750 and 1250° C.
Read more about: Transfer
Notes: These descriptions are for small and medium silkscreen workshops and flat objects. The large ceramic industry, especially tableware companies have other, more automatic screen printing applied to parts: cylindrical objects, borders, backgrounds of plates, cups, curved objects, etc.
The next section; Screen printing (1) Making a design
