They're rolled in rings (7)
I believe the answer is:
napkins
'rings' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe there's an association between them I don't understand?
'they're rolled in' is the wordplay.
I cannot quite see how this works, but
'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for napkins that I've seen before include "Cloth squares to protect clothes while eating" , "Serviettes" , "Pieces of table linen" .)