Surface film made from a paint (6)
I believe the answer is:
patina
'surface film' is the definition.
(I've seen this in another clue)
'from a paint' is the wordplay.
'from' indicates anagramming the letters (from the letters).
'a'+'paint'='apaint'
'apaint' anagrammed gives 'PATINA'.
'made' is the link.
(Other definitions for patina that I've seen before include "Fine coating on surface" , "Sheen produced by age and polishing" , "Distinctive surface acquired over time" , "Fine layer on surface (from oxidisation or handling)" , "Surface coating that comes with age" .)