When ordering folders, the capacity must be specified.
As you would expect, 5mm capacity folders mean the spine (gusset) is 5mm wide. Folders with a 5mm capacity can comfortably hold approximately 40 pieces of standard copier paper. 5mm capacity is the most popular folder capacity ordered through duncanbaines.com
10mm capacity folders have a spine (gusset) which is 10mm wide! They can comfortably hold 70 sheets of standard copier paper.