Artist at Royal Institute draws unusual objects (8)
I believe the answer is:
rarities
'unusual objects' is the definition.
(rare or unusual items)
'artist at royal institute draws' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'at' says to put letters next to each other.
'royal' becomes 'r' (abbreviation).
'institute' becomes 'i' (common abbreviation as in MIT).
'draws' becomes 'ties' ('tie' can be a synonym of 'draw').
'ra'+'r'+'i'+'ties'='RARITIES'
(Other definitions for rarities that I've seen before include "Is a trier for scarce things" , "Uncommon things" , "pearls" , "They're very unusual" , "Things seldom encountered" .)