Larger than quarto (5)
I believe the answer is:
folio
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">larger than quarto</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for folio that I've seen before include "Body of written work" , "Manuscript sheet" , "Two-leaf sheet" , "Four pages" , "Leaf of paper" .)