The term quarto refers to the size of paper many of Shakespeare’s plays were originally printed on. A quarto is formed when a full sheet of paper is folded in fourths, creating eight pages. Quartos were about half the size of folios, and cheaper to produce. Eighteen, or half, of the plays in the First Folio were printed separately as quartos. Scholars refer to these printings by the letter Q followed by the edition number. For example, Q1 refers to a first quarto edition of a play.