Grammage are the same weight paper having different cut size. However, a sheet of common copy paper that has a basis weight of does not have the same mass as the same size sheet of coarse paper (newsprint). In the former case, the standard ream is 500 sheets of paper, and in the latter, 500 sheets of paper. Here are some basic ream sizes for various types of paper. Units are inches except where noted. Sheets can be cut into four sheets, a standard for business stationery known conventionally as "letter sized paper". So, the ream became commonly used. The book-paper
Units of paper quantity sheets of vellum or parchment, i.e. 8 leaves, 16 sides. The term "quaternion" (or sometimes "quaternum") designates such a quire. A quire made of a single folded sheet (i.e. 2 leaves, 4 sides) is a "bifolium" (plural "bifolia"); a "binion" is a quire of two sheets (i.e. 4 leaves, 8 sides); and a "quinion" is five sheets (10 leaves, 20 sides). This last meaning is preserved in the modern Italian term for quire, "quinterno di carta". Formerly, when paper was packed at the paper mill, the top and bottom quires were made up of slightly damaged sheets ("outsides") to protect