Many packets of paper, one imagines (6)
I believe the answer is:
dreams
'one imagines' is the definition.
(I've seen this in another clue)
'many packets of paper' is the wordplay.
'many packets of' becomes 'drea' (I can't justify this - if you can you should give a lot more credence to this answer).
'paper' becomes 'ms' (abbreviation for manuscript).
'drea'+'ms'='DREAMS'
Can you help me to learn more?
(Other definitions for dreams that I've seen before include "Fantasies; fantasises" , "Fantasy ambitions" , "Imaginings" , "'We are such stuff / As dreams are made on' (The Tempest)" , "Fancies" .)