Lamination
Also called Matt lamination, gloss lamination, soft-touch lamination
A very thin plastic film bonded with heat onto a cover or jacket. Gloss, matt or soft-touch (velvety to the hand), it protects the print and changes how the book feels.
In practice
Gloss lifts pictures but reflects; matt is understated but shows scratches; soft-touch is lovely to hold and keeps fingerprints. Laminating also makes the cover harder to recycle, which some publishers weigh. Say whether it is outside only or both sides, and ask for a sample of the film on your stock.