Smooth stuff (6)
I believe the answer is:
sateen
'smooth stuff' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'stuff' is the wordplay.
I cannot really understand how this works, but
'stuff' could be 'sate' (I've seen this in another clue) and 'sate' is present in the answer.
The remaining letters 'en' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sateen that I've seen before include "Shiny cloth used for furnishings" , "Closely woven cotton fabric resembling satin" , "Sea net could provide a glossy fabric" , "Shiny cloth found in senate" , "Cotton fabric with a satiny finish" .)