Screen printing is sometimes called silk screening. It is a type of printing technique, usually used for flat surfaces. It is often used to decorate t-shirts and banners.
The procedure is straightforward and simple, but tedious. First, a screen (or a fine mesh material) is stretched, like a canvas, in a frame. Then, a design is made by masking out the areas that won’t be printed. This is placed against the surface. Then, ink is liberally applied on top of the screen, then pressed into the surface with a squeegee. The ink must then be dried, either by the application of heat, or by hanging under the sun. In mass production, the material is sent on a conveyor belt through a heat-tunnel. The permanence of the ink is affected by the quality of the materials and the curing or heating method.
Screen printing is easiest when only one color is used. However, it is possible to have multi-colored designs. This is done by creating different screens, each corresponding to a particular color. While some may still choose to do this by hand, it is much faster to use a rotary press that will align the different screens. Through today’s technological advances, some screen printing machines fully automate all the steps except for loading and unloading the materials.
To create “masks” that block out the ink, it is possible to use masking fluid—if the design requires just one or two colors. For more complicated designs, however, photosensitive emulsions are required.