Criminal jumps over the top with raw material used for making sheets (6)
I believe the answer is:
cotton
'the top with raw material used for making sheets' is the definition.
I can't tell whether this defines the answer.
'criminal jumps over' is the wordplay.
'criminal jumps' becomes 'cott' (I can't explain this - if you can you should give a lot more credence to this answer).
'over' becomes 'on' (I've seen this in other clues).
'cott'+'on'='COTTON'
Can you help me to learn more?
(Other definitions for cotton that I've seen before include "Creamy-white natural fibre" , "Soft fabric and fluffy wool (6" , "Fibre including kapok" , "Natural cloth" , "Substance like fine wool" .)