Some puppet characters make an impression (4)
I believe the answer is:
etch
'make an impression' is the definition.
(to etch is to make an impression in something)
'some puppet characters' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'ETCH' can be found hidden inside 'puppet characters'.
(Other definitions for etch that I've seen before include "Cut lines with acid" , "Make carvings" , "Chase" , "Carve into surface, impress deeply" , "Engrave deeply" .)