Produce artwork that's required by supermarket chain (4)
I believe the answer is:
etch
'produce artwork that's' is the definition.
I can't judge whether this defines the answer.
'required by supermarket chain' is the wordplay.
'required by' indicates the answer is hidden within the clue (the answer is required to spell part of the clue).
'ETCH' can be found hidden inside 'supermarket chain'.
Can you help me to learn more?
(Other definitions for etch that I've seen before include "Corrode" , "Incribe" , "Cut into a block used for printing" , "Engrave deeply" , "Use acid to design on metal or glass" .)