
A coating applied to the face material on the side opposite the printed surface to provide increased opacity to the face material and/or to prevent migration between adhesive and the face material and/or to improve anchorage of adhesive to face material.
Found on
http://www.encyclo.co.uk/local/20829

A coating that is applied onto the non-printing side of paper to add to the opacity of that paper. Reference, opacity.
Found on
https://www.encyclo.co.uk/local/22539
No exact match found.