A slip sheet is an unprinted, often slightly absorbent piece of paper placed manually or mechanically between newly printed sheets as they stack in the delivery tray. It prevents the wet ink on the front of one sheet from offsetting onto the back of the sheet resting on top of it. This technique is especially common when running heavy ink coverage on slow-drying coated stocks.
Heard on the job
We're getting some serious set-off on these heavy solids, so have the helper throw a slip sheet between every pull.
Insider tip
Automated presses use anti-offset powder spray to do this job mechanically, but hand slip-sheeting is still required for specialty screen printing or fine art editions.