Supplier of paper one artist ordered (9)
I believe the answer is:
stationer
'supplier of paper' is the definition.
(a stationery shop might sell paper)
'one artist ordered' is the wordplay.
'ordered' indicates an anagram.
'one'+'artist'='oneartist'
'oneartist' with letters rearranged gives 'STATIONER'.
(Other definitions for stationer that I've seen before include "I supply rulers: for example" , "Retailer of writing materials etc" , "Writing-materials shop" , "Tears into (anag.)" , "Seller of writing materials" .)