Instrument with the stamp of fine stuff (8)
I believe the answer is:
organdie
'fine stuff' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'instrument with the stamp' is the wordplay.
'instrument' becomes 'organ' (organ is a kind of instrument).
'with' means one lot of letters go next to another.
'the stamp' becomes 'die' (I've seen this in another clue).
'organ'+'die'='ORGANDIE'
'of' is the link.
Can you help me to learn more?
(Other definitions for organdie that I've seen before include "Fine slightly stiff cotton dress fabric" , "A stiffened muslin; I groaned (anag.)" , "Oddly ignored a fine cotton muslin" , "Fine material" , "I raged on about the fabric" .)