Quarto (paper format)
Quarto (from Latin quartus - 'the fourth', plural quartos , abbreviated 4 ° ) describes an old exercise book or book format (other formats see there). One also speaks of four or four formats.
The name refers to the number of sheets (double pages) that are created per folding sheet. With the quart, the sheet of paper is folded twice to form four sheets (eight pages per sheet).
The size of a sheet of paper changed over time. At first it was completely arbitrary and, depending on the age, depended on the size of the parchment, later on the shape of the ladle. From around 1850 onwards, a book format that is now historical in the library system (other formats see there) was established. A distinction is made between small quarters ( small 4 °) = approx. 23–26 cm and large quarters (large 4 °) = approx. 35–40 cm.
Since 1883 efforts were made in Germany to standardize the bow sizes. Twelve normal formats were created, of which the number 1 was unfolded (also: "unbroken" or "in plano") measuring 33 cm × 42 cm.