Strong material Art composed with his partner's all the rage (9)
I believe the answer is:
tarpaulin
'strong material' is the definition.
'tarpaulin' can be an answer for 'material' (tarpaulin is a kind of material). I'm not sure about the 'strong' bit.
'art composed with his partner's all the rage' is the wordplay.
'composed' indicates anagramming the letters.
'with' is a charade indicator (letters next to each other).
'his partner's' becomes 'paul' (I can't justify this - if you can you should believe this answer much more).
'all the rage' becomes 'in' (both can mean trendy).
'art' anagrammed gives 'tar'.
'tar'+'paul'+'in'='TARPAULIN'
Can you help me to learn more?
(Other definitions for tarpaulin that I've seen before include "protective headgear" , "protective cover" , "sailor's hat" , "[SHHET]" , "Waterproof canvas used as covering" .)