Tuesday, 4 August 2009

What is screen printing?

Screen printing is a technique derived from stencils. The basic difference is that the ink goes through a fine tensed mesh. Originally this mesh was made from silk, hence the name ‘silk screen printing’, but nowadays it has been substituted by synthetic fibres that maintain tension even when wet. This mesh is held tense by a frame, forming the screen.

The process to obtain the printed image consists on blocking the parts of the screen that must not be printed with an emulsion or varnish. Then the screen is laid on the surface to be printed and ink is forced though the mesh, with the help of a flat rubber blade, passing only where the screen was not blocked, and printing only the image. If the image has more than one colour, one screen will be needed for each and all of them must contain a registration code so that the image will coincide exactly. In the modern days, it’s not even necessary to draw directly on the screen; it’s normally blocked by using a light sensible emulsion and a photolithograph of the image. This means any image can be easily transferred on to the screen.

Screen printing allows numerous prints, without loosing definition of the image. It’s used to print on any kind of object and practically any material. It’s mostly used for decorative purposes and publicity.

This is my own design, printed at home on the long board I de-padded for my summer extension not long ago.