Silk-screen printing dates back to at least 500 a.d., when it was used in both China and Japan to print works of art. In Europe, it first appeared in the fifteenth century, when it was used to manufacture religious images and playing cards.

The process of silk-screen printing is relatively simple. The printed stencil (usually made of silk) is stretched over a frame. A viscous ink is then forced through the stencil onto the subject--which can include cloth, paper, wood, plastic, metal, or glass--with a "squeegee," a soft-bladed tool which scrapes across the surface.

The versatility of the method made it a popular means of decorating household furnishings in the eighteenth and nineteenth centuries. With the 1907 patenting of an automated process by American Samuel Simon, the commercial applications of silk-screen flourished. Today, artificial fabrics have, for the most part, replaced silk as the stencil medium and the technique is primarily used to impress inked patterns on mass-market clothing. Light-sensitive screens are used to reproduce photograph s and illustrations, such as those often seen on T-shirts. The ability of silk-screen printing to apply inks of various thicknesses makes it possible to print weather-resistant images on outdoor signs and billboards.