The diffusion of cured ink substances needs time, and is temperature related. Stable results ondiffused ink substances can be expected after several days or also after a longer time periodrelated to the shelf life of a product.Reasons for migration:• Residue of monomers• Photoinitiators• Decomposition product of photoinitiators• Ink additives• Incomplete curingIn a heavy set-off situation also normally non-migrating pigments and binders may transfer tothe filling product.There are “quick and dirty” methods for testing for possible ink migration, which can be madewithin minutes of printing. But these methods are no guarantee for low migration.One, a detectable and distinct “print” smell is an indication of migration. Two, when an ethanolsoaked paper towel is wiped across the print and the towel shows ink residue (the ink’s color),then there is the probability of improperly cured inks and a high risk of set-off and/or migration. .