Artist’s percentage twice has inflated (6)
I believe the answer is:
cubist
'artist's' is the definition.
(cubist is a kind of artist)
'percentage twice has inflated' is the wordplay.
'percentage' becomes 'cut' (cut is a kind of percentage).
'twice' becomes 'bis' (I've seen this in other clues).
'has inflated' is an insertion indicator (some letters make another word larger).
'cut' going around 'bis' is 'CUBIST'.
(Other definitions for cubist that I've seen before include "Maybe multifaceted" , "Painter like Picasso" , "modern artist" , "Braque or Picasso, for example" , "Artist as Picasso, Braque" .)