Simple boxes or empty case for ceramic ware (9)
I believe the answer is:
porcelain
'ceramic ware' is the definition.
(porcelain is a kind of ceramic ware)
'simple boxes or empty case' is the wordplay.
'simple' becomes 'plain' ('plain' can be a synonym of 'simple').
'boxes' means one lot of letters goes inside another (the outside letters must 'box' inside letters in).
'empty' suggests removing the centre.
'case' with its centre removed is 'ce'.
'or'+'ce'='orce'
'plain' placed around 'orce' is 'PORCELAIN'.
'for' is the link.
(Other definitions for porcelain that I've seen before include "fragile goods" , "Fine earthenware" , "Jasper, perhaps" , "Translucent pottery" , "Fine ceramic ware" .)