Manufacture of a prime cheap material (6-5)
I believe the answer is:
papier-mache
'material' is the definition.
(papier-mache is a kind of material)
'manufacture of a prime cheap' is the wordplay.
'manufacture of' is an anagram indicator (I've seen this in other clues).
'a'+'prime'+'cheap'='aprimecheap'
'aprimecheap' with letters rearranged gives 'PAPIER-MACHE'.
(Other definitions for papier-mache that I've seen before include "Pulp which can be painted when dry" , "Paper medium for moulding items" , "Modelling material" , "Made of a dried pulp" , "Light, hardmoulded material" .)