For you guys starting out in screen printing you may have heard the term ‘off-contact’ before.
Off-contact simply means the gap between the platen and bottom of the screen frame.
Its purpose is to prevent ink from sticking to the substrate (substrate is the item being printed e.g. t-shirt) when a squeegee is pulled across the screen. Off-contact guarantees that the screen mesh will immediately snap back from the substrate as the squeegee is moved across the stencil, resulting in a good print.
If there is no off-contact during screen printing, ink will most likely smear causing problems including an imperfect print. Not having off-contact will also cause difficulty lifting the screen after a pass.
Mind the Gap
For DIY screen printing presses, there are several methods to create the off-contact. The easiest and relatively successful method is to use a ‘shim’.
Common “shims” are popsicle sticks, index cards, cardboard, plastic ruler, or my favourite, coasters.