Screen printing is a printmaking technique that creates a sharp-edged image using a stencil. A screen print or serigraph is an image created using this technique.
A screen is made of a piece of porous, finely woven fabric (originally silk, but typically made of polyester or nylon since the 1940s) stretched over an aluminum frame. Areas of the screen are blocked off with a non-permeable material -a stencil- which is a positive of the image to be printed; that is, the open spaces are where the ink will appear.
The screen is placed on top of a piece of dry paper or fabric. Ink is placed on top of the screen, and a squeegee (rubber blade) is used to push the ink evenly into the screen openings and onto the substrate. The ink passes through the open spaces in the screen onto the paper or fabric below; the screen is lifted away and then the squeegee is pushed back across the screen, with the screen lifted, "flooding" the ink into the screen. The screen can be re-used after cleaning. If more than one colour is being printed on the same surface, the ink is allowed to dry and then the process is repeated with another screen and different colour of ink.
While the public thinks of garments in conjunction with screen printing, the technique is used on tens of thousands of items, including birthday cake designs, decals, clock and watch faces, and many more products. The vast majority of silk-screen printings are monochromatic. Graphic screen printing is widely used today to create many mass or large batch produced graphics, such as posters or display stands. Full colour prints can be created by printing in CMYK (cyan, magenta, yellow and black).