Tattoo artist's supplies (4)
I believe the answer is:
inks
'tattoo artist's supplies' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for inks that I've seen before include "Printing fluids" , "Fluids from cuttlefish" , "Liquids used for printing" , "Printers' mediums" , "Sink beneath writing fluids" .)