The screen frame is one of the important equipment for making the screen. No matter what kind of mesh is selected, the slack mesh must be tightened on the screen frame before making the screen graphics. Therefore, the quality of the screen frame directly affects the quality of the screen printing.
1. Types of screen frames: roughly divided into three types: wooden frames, aluminum frames, and steel frames.
（1） Wooden frame: low cost and easy to handle, usually used in small-size screens for manual printing. However, the wooden frame has low strength and is greatly affected by temperature and humidity. It is not suitable for the requirements. The printed matter with high overprint accuracy has a relatively short life.
（2）Aluminum frame: small specific gravity, relatively light, easy to handle even large screen frames, its significant advantages are: low cost (of course more expensive than wooden frames), light weight, wide selection of cross-sections, can be used to stretch a variety of The mesh is resistant to rust and easy to clean. But it is not resistant to acids and alkalis, and not as strong as a steel frame.
（3）Steel frame: It has good sturdiness, but it is heavy and easy to rust. It needs proper treatment (galvanizing or painting) and the cost is relatively high.
2. Conditions for selecting a screen frame:
（1）The screen frame must have a certain strength, and will not be deformed under certain conditions during stretching and printing, so as to ensure the precise size of the screen frame, thereby ensuring the accuracy of plate making and printing.
（2） Under the premise of ensuring the strength, try to choose a lighter one.
（3）The adhesive surface of the screen frame and the screen must be rough, and the metal frame generally needs to be roughened on the surface to ensure a firm bond.
（4） No deformation under contact with solvents, water and temperature changes.
（5） The appropriate screen frame should be selected according to different printing patterns to reduce waste and facilitate operation.
3. Selection and treatment of screen frame size:
（1） Selection of screen frame size:
Depending on the area to be printed and the type of printing, there should usually be enough space around the printable area.
（2）Processing of the screen frame:
Roughening: The metal frame with a smooth surface must be roughened before use and sanded with sandpaper
Treatment: The polished screen frame must be thoroughly degreasing treated with solvent (acetone) before use, and oily cleaning agents must not be used.
Cleaning of the old screen frame: The used screen frame must be removed from the remaining screen, ink and photosensitive glue, and the edges must be cleaned to avoid tearing the screen.