A screen is a piece of mesh woven in a lattice which is used for the production of screen prints. The screen is stretched on a frame and the holes in areas other than the image are filled. When printing, ink is placed over this screen and forced through the pin holes that have not been blocked out so that it is printed on the substrate.

As can be inferred from the name “silk screen printing”, screens were formerly produced from silk fiber. Today, they are commonly made of chemical fibers such as tetron (polyester) and nylon. Stainless steel screens are sometimes used for high-resolution printing on metal and wood in industrial applications. Tetron screens are sometimes dyed yellow to prevent light from reflecting diffusely during exposure in the photo emulsion method.

Screens are woven into a lattice and come in different degrees of density. This mesh　count is expressed as the number of threads per inch (tpi). Commercially available types range from 80 tpi to 500 tpi; the higher the number, the more dense the mesh. Normally, screens with a mesh count of around 200 tpi are used for print work. Screens with a lower mesh count should be used when printing on fabric or using thick ink, and those with a higher mesh count when using runny ink with finer particles or printing patterns that have fine details.

A screen must first be stretched on a wooden or metal frame before use. This can be entrusted to a specialist company or be carried out on a machine called a screen stretcher at a printmaking workshop, but you can also do this yourself using screen stretching pliers (Hippaler, etc.). Using a machine costs money but this will ensure that the screen is always stretched reliably with a uniform tension. If you do it yourself, the screen can be stretched to the desired tension and the mesh can be changed at will, but if you are not accustomed to the procedures, you could end up tearing the screen. The screen will have to be replaced if it becomes slack with use or develops a hole in it. Screens can be purchased at art supply stores selling printing tools and printing supply stores.