The most common and most likely answer to this crossword clue is the 5 letter word QUIRE
Q
U
I
R
E
Buddy explains!
The straight part
We know that "paper" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case paper = quire.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does QUIRE mean?
QUIRE noun- One-twentieth of a ream of paper; a collection of twenty-four or twenty-five sheets of paper of the same size and quality, unfolded or having a single fold.
- A set of leaves which are stitched together, originally a set of four pieces of paper (eight leaves, sixteen pages). This is most often a single signature (i.e. group of four), but may be several nested signatures.
- A book, poem, or pamphlet.
- To prepare quires by stitching together leaves of paper.
- A choir.
- One quarter of a cruciform church, or the architectural area of a church used by the choir, often near the apse.
- To sing in concert.