Slip additives — commonly erucamide or oleamide in polyolefin films — are incorporated into the polymer and migrate to the surface over time, forming a low-friction layer that lets film run through converting equipment without sticking.
For a coating formulator this is a persistent problem. That same migrated layer is a low-surface-energy contaminant sitting exactly where you need adhesion. A film that printed well when fresh can fail weeks later as more additive blooms to the surface.
It explains a specific and common failure pattern: adhesion that passes on a new roll and fails on aged stock of the same film, with no change in the ink or the press.
The mitigations are to specify low-slip or slip-free film for printed surfaces, to check dyne level on the actual roll, and to print film as fresh as practical.