Off contact is the distance between the bottom of the screen mesh and the top of the garment being printed .The purpose of off contact is to keep your print sharp and crisp. This is accomplished by the screen snapping off the garment and releasing the ink on the garment. The squeegee moves over the screen, pushing the ink as it goes, and the screen drops down and touches the garment. Well as the squeegee moves the screen snaps off the shirt, releasing a deposit of ink on the shirt.
Besides releasing the deposit of ink on the shirt, off contact keeps the screen from constantly touching the print. Off contact also helps reduce ink build up when printing wet on wet. Too much ink build up can cause blurry prints, so keeping a good off contact distance can help minimize this when printing wet on wet.
Off contact distance is usually 1/6" to 1/8" inch depending on the type of garment you are printing on and the type of ink you are using. Increasing off contact can increase the amount of ink deposited on the shirt. Decreasing and using a smaller off contact distance reduces the amount of ink deposited on the shirt.
Discharge and water base ink usually use 1/6" of an inch for off contact- equal to the thickness of a dime. Off contact for printing plastisol ink is usually 1/8" of an inch for thickness and just a little more for printing hoodies and sweatshirts!