Hinges are necessary when screenprinting in series to make sure the screen registration remains stable, and your image lines up in the same place on each print. Hinges connect the screen to the printing base, and allow you to swing your screen up without disturbing its orientation. Fabricated from durable, rust resistant cast aluminum. The sturdy, thumbscrew-adjusted clamps mean you don't have to screw and unscrew hinges each time you want to change a screen! Just screw the bottom of the Hinge Clamp onto your printing base and secure the clamps onto your screen. Positive locking means perfect registration and precise control in every print!