The real sort of material (7)
I believe the answer is:
leather
'material' is the definition.
(I've seen this before)
'the real sort' is the wordplay.
'sort' indicates anagramming the letters.
'the'+'real'='thereal'
'thereal' anagrammed gives 'LEATHER'.
'of' acts as a link.
(Other definitions for leather that I've seen before include "Material made from animal skin" , "Morocco, perhaps" , "Cured animal hide" , "Processed animal skin" , "kid, perhaps" .)