A measure of volume size, used for medium sized or average codexes.

The size of a volume created by folding a sheet in half once, then rotated 90 degrees and folded in half again. This creates a quire of four leaves (eight pages) that is one-quarter the size of the original sheet. Abbreviated 4o or 4to.

  • Arabic:
    قطع الربع
  • French:
    In-quarto (in-4°)
  • Italian:
  • Spanish:
    En cuarto; In-quarto

Michelle Brown, Understanding Illuminated Manuscripts (Malibu, CA: J. Paul Getty Museum in association with the British Library, c1994).