Material lifted off punch bags (7)
I believe the answer is:
chiffon
'material' is the definition.
(I know that chiffon is a type of material)
'lifted off punch bags' is the wordplay.
'lifted' is a reversal indicator (going up in down clue).
'punch' becomes 'chin' (slang term meaning to punch someone on the chin).
'bags' means one lot of letters goes inside another (bag can mean secures or steals).
'off' written backwards gives 'ffo'.
'ffo' inserted into 'chin' is 'CHIFFON'.
(Other definitions for chiffon that I've seen before include "Thin light fabric" , "Fine transparent fabric" , "Light silk/nylon fabric" , "dress material" , "Fine (semi)transparent fabric" .)