Reluctant in the Civil Service to produce materials (6)
I believe the answer is:
cloths
'materials' is the definition.
(I know this)
'reluctant in the civil service' is the wordplay.
'reluctant' becomes 'loth' (if you are loth to do something you are reluctant).
'in the' indicates putting letters inside.
'civil service' becomes 'CS' (abbreviation).
'loth' inserted inside 'cs' is 'CLOTHS'.
'to produce' is the link.
(Other definitions for cloths that I've seen before include "Wipers?" , "Pieces of material as for drying dishes" , "Rags" .)