In the poorest ateliers is where you can see fine pictures! (4)
I believe the answer is:
tate
'where you can see fine pictures' is the definition.
The definition suggests a singular noun which matches the answer.
'in the poorest ateliers is' is the wordplay.
'in' says the answer is hidden in the clue.
'TATE' is hidden in the letters of 'poorest ateliers is'.
Can you help me to learn more?
(Other definitions for tate that I've seen before include "- - Modern: art gallery" , "Art Gallery donor" , "Name of two London galleries" , "Britain/Modern gallery" , "Either of two galleries in London" .)