Folio
individual sheet of a book or manuscript numbered on one side
When talking about manuscripts, and printing in general, a folio is a sheet, which is used on both sides. One of the sides is known as recto, the other one as verso.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/MS_65_fol_39v.jpg/220px-MS_65_fol_39v.jpg)
When talking about manuscripts, and printing in general, a folio is a sheet, which is used on both sides. One of the sides is known as recto, the other one as verso.