3M Lapping Film
3M imperial lapping film is a range of very fine, very accurate film backed abrasives designed for producing exceptionally close tolerance polished surfaces on hard materials.
Precisely graded abrasive particles of Aluminium Oxide are electrostatically adhered to the film which is then coated with a resin that locks the abrasive particles in and prevents grit transfer when moving through the grades.
The reverse side is coated with pressure sensitive adhesive (PSA) so you can peel the backing paper off and stick them to a surface. The adhesive is a much stronger, heavy duty version of the stuff on a post it note - it is incredibly sticky.
The sheets are 8-1/2 x 11 inches (roughly A4).