This is a form of stencilling in which a silk screen allows ink to pass through the parts of it that are not blocked by an impenetrable membrane. An even layer of ink is applied to the screen which is laid on top of the flat material. The process is ideal for printing T-Shirts and other garments. It can also be used for making printed circuit boards for use in electronic equipment. In this case a special conductive ink is required and the ink replaces the need for wires.

Originally called silk-screen printing because of its silk-based stencils, screen printing has become important in the production of a wide array of manufactured items, including decorative panels, printed circuit boards, touch-sensitive switches, plastic containers, and printed garments. Stencils for commercial screen printing are usually produced by photomechanical means. A fine synthetic fabric or metal mesh is stretched over a rectangular frame, and a photopolymer coating is applied to the entire surface. Exposure of the photopolymer through a film positive causes it to harden in the areas not intended to print. The unexposed material is then washed away to create the open areas of the stencil. In the printing press, this screen is pressed against the surface to be printed, and ink is forced through the open areas of the stencil with a rubber squeegee.

Presses for screen printing range from simple manual devices for the small-scale printing of T-shirts and banners to large sheet-fed presses for multicolour, high-volume commercial applications. The process is distinguished by its ability to print finely detailed images on practically any surface, including paper, plastics, metals, and three-dimensional surfaces. It is also the only major printing process that is routinely used to produce images that are not meant to be viewed. The circuit patterns in touch-sensitive switch panels, for example, are screen-printed with special conductive inks.