The screen frame is a structure that the woven mesh is stretched upon and adhered to. Screen frames come in a variety of shapes and sizes, depending on the size of the art work and printing surface. The mesh is either stapled or glued to the frame with sufficient tension to provide a flat printing surface that will not buckle.
Typically, frames are made out of wood or aluminum. Personally I recommend aluminum frames over wood because they are easily cleaned and can be reused indefinitely without losing their shape. Wood screens will be fine for a while but repeated water exposure tends to warp the frame over time. Over time, with extended use, both wood and aluminum screen meshes will lose some tension which may result in poorer quality printing results. If you start to notice this occurring it’s best to have the screens re-meshed.
Always choose a screen frame that is larger than the area you are attempting to print by at least 2 inches on every side. This will make your life easier when applying emulsion, exposing artwork and printing.