Graphic Design for Ceramic Tiles

The development of a computer based design system for ceramic tiles forms part of a BriteEuram project aimed at providing automated quality control for ceramic tile production. The design system is expected to provide a priori information about each tile design to the quality control inspection stations. The differences between graphic design for paper and graphic design for ceramic are discussed, and the additional information required by the quality control system is considered. Traditional ceramic tile design is performed on paper using a wide variety of conventional tools: pens, brushes, air brushes, etc. A completed design is separated by hand, and a silk screen produced for each colour separation. These silk screens are used to print the design on the tile biscuit, which is then fired in a kiln. Tile design appears to have much in common with the graphic design used for conventional paper products, and hence it might be supposed that existing computer design tools can be used for ceramic tiles. Some customisation is desirable, if only to provide an annotation mechanism for passing extra design information to the quality control system. Design for ceramics and design for paper products differ, however, in several ways in the constraints they place on separations: (1) ceramics require much coarser half-tone screening than paper; (2) magenta and red inks are difficult to make for ceramics; (3) there are no standard inks for ceramics, each manufacturer makes his own; and (4) colours mix in unpredictable ways, owing to the reactions in the kiln between the chemicals used to pigment the ceramic. These constraints mean that conventional CMYK separation is of little use in ceramic tile design. This paper describes a computer design system for ceramic tiles consisting of a standard graphic design package, with suitable annotation facilities and appropriate extensions, and an automatic separation utility tailored for the needs of ceramics. Such a computer based design system has several advantages over manual design: (1) it allows the quality control system access to the design data, incorporating annotations provided by the designer specifically for quality control; (2) it allows separations to be produced automatically, freeing the designer to spend more time designing; and (3) it allows easier previewing of different colourways, and to some extent, aids in experimenting with various design elements. Weighed against this are the disadvantages that (1) the designer must learn a new tool which replaces rather than augments her existing repertoire of tools; and (2) no computer design package is yet capable of achieving the wide range of effects possible with traditional tools.