fo•lio | \ 'fō-lē-'ō \
: a book of the largest size
“Folio” is a term originally used by printers to describe oversized books. Libraries add the folio designation to call numbers to indicate that the item is shelved separate from the general collection. At Sawyer Library the folio designation is applied to books with a height greater than 38 cm., and art books (including photography) taller than 43 cm.