Set-off is primarily caused by the printed ink not drying completely before the sheet is stacked onto the next one. The main contributors are high press speeds and, most crucially, high Ink Density. This is directly linked to TIC (Total Ink Coverage), which is the total percentage of CMYK ink in any given area.

Excessive TIC significantly extends the required Drying Time for the ink. When heavy ink coverage is combined with the mechanical pressure from the weight of the paper stack, the semi-dry ink is forced to transfer to the back of the sheet lying above it. Effective Prepress management, focused on reducing TIC to the safe limit defined in the ICC Profile, is the primary preventative measure against this defect.