Plaster finish (6)
I believe the answer is:
stucco
'plaster finish' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stucco that I've seen before include "Fine decorative plaster" , "Durable finish for walls" , "Mouldable wall plaster" , "Fine plaster used on wall surfaces" , "Plaster used to coat walls" .)