Don't spare the printing material - this will hold it (7)
I believe the answer is:
inkwell
'don't spare' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'printing material this will hold it' is the wordplay.
'printing material' becomes 'ink' (I've seen this in another clue).
'this will' becomes 'll' (contracted form, as in 'he'll' - 'he will').
'hold' is an insertion indicator.
'it' becomes 'we' (I can't explain this - if you can you should believe this answer much more).
'ink'+'ll'='inkll'
'inkll' enclosing 'we' is 'INKWELL'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for inkwell that I've seen before include "Small pot for holding writing fluid" , "Reservoir for writing fluid" , "Writing fluid holder" , "Old desktop pot" , "Desk reservoir" .)