Printer ink (5)
I believe the answer is:
toner
'printer ink' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for toner that I've seen before include "Skin-cleansing lotion" , "Skin improver" , "Astringent liquid (to improve skin)" , "Material for printer" , "Powder used in printers" .)