Graphic art includes the techniques of sgraffito, mosaic, and batik. They are all three based on clear drawing. If color is used, it is an sharply defined areas without total gradations; the painter's way of merging and overrunning colors is technically impossible.
Each technique derives particular charm from the effect of the material in the method of working at. In sgraffito it is wall plaster, in mosaic the small colored stones, or tesserae, in batik the cloth, generally real silk. Each of these materials has a pronounced texture which defines the picture plane strongly and the best sgraffito and mosaic combines the design with the architecture. The raison d'�tre of both techniques is to decorate a wall, and batik, too, achieves its full effect only as a wall hanging.
All three techniques will succeed with anyone who can express the graphic idea clearly and simply on paper. This craft can easily be learned and does not need much practice - much less than professional engraving or wood carving. As graffito and mosaic will, however, require the help of an experienced builder with the preparation of the plasterwork. Useful hints can be picked up from watching his work, which may not be familiar from an acquaintance with only finished plaster. Batik, on the other hand, is a domestic occupation. The craft is easily learned if one knows a little about ironing and follows the simple directions for the use of cold dyes.
All three techniques require this the design to well thought out in advance. This point was to set to work with only a vague idea of what it should look like. Both design and procedure must be well-planned.
Sgraffito means "scored" or "scratched". The Italian term is always used in English.
The wall is prepared for sgraffito by giving it two or more coats of different colored plaster. The upper coat is either cut away to the shape of the design, or the design is scored out in line drawing, which then shows up in the color of the under layer. The process can be easily understood by smearing a slate or other dark ground with a chalk paste (without a binder) and, after it has dried, drawing into the white surface with a metal or wooden point; this scrapes away the white, leaving a dark line.
The earliest sgraffito designs were made in this way: the wall was first rendered with a coat of mortar mixed with soot, and this was then masked with a layer of whitewash. The design was scored into the white with q metal or wooden stylus. At first this procedure was practiced only by ordinary builders for simple ornamental decoration or imitations of stone blocks.
The first sgraffito design of any artistic value dates from the thirteenth century and is in the cloisters of Magdeburg cathedral. Strictly speaking, it is only a drawing scratched into the plaster while it was soft, and presumably afterwards colored with a brush, since it would not otherwise have been visible unless seen with side lighting to throw shadows. Today only a few traces of color remain. This attractive sgraffito medium is no longer used, but it would be worthwhile reviving its practice.
Sgraffito into lime wash over mortar mixed with soot was used to greatest effect during the Renaissance.
Bohemia has the largest number of examples. Prints and engravings by famous artists were the most popular models. Enlarged on walls to monumental proportions, they look like rough pen and ink drawings. In the same period artists hit upon the idea of using calcareous earth pigments instead of soot to color the mortar, covering it with a thin coat of plaster in a contrasting color instead of the lime wash.
It is difficult to make close hatching in plaster, so shadows and dark areas were cut out in solid pieces. The thickness of the top layer made the edges of all scorings and cut-out areas stand out in relief. This technique was at first used almost exclusively for the ornamental decoration of paneling, but it is now commonly used in all sgraffito work.