and Timothy Graham point out, in their Introduction to Manuscript Studies, that "the quire was the scribe's basic writing unit throughout the Middle Ages". Guidelines are then made on the membrane. They note "'pricking' is the process of making holes in a sheet of parchment (or membrane) in preparation of its ruling. The lines were then made by ruling between the prick marks ...The process of entering ruled lines on the page to serve as a guide for entering text. Most manuscripts were ruled with horizontal lines that served as the baselines on which the text was entered and with vertical bounding lines that marked the boundaries of the columns". Usage Most of the finer sort of medieval manuscripts, whether illuminated or not, were written on vellum. Some Gandharan Buddhist texts were written on vellum, and all Sifrei Torah (Hebrew: ספר תורה Sefer Torah; plural: ספרי תורה, Sifrei Torah) are written on kosher klaf or vellum. A quarter of the 180 copy edition of Johannes Gutenberg's first Bible printed in 1455 with movable type was also printed on vellum, presumably because his market expected this for a high-quality book. Paper was used for most book-printing, as it was cheaper and easier to process through a printing press and to bind. The twelfth century Winchester Bible was printed on 250 calfskins, with a need of over 2,000 hides to be collected for the preparation and creation of the bible. In art, vellum was used for paintings, especially if they needed to be sent long distances, before canvas became widely used in about 1500, and continued to be used for drawings, and watercolours. Old master prints were sometimes printed on vellum, especially for presentation copies, until at least the seventeenth century. Limp vellum or limp-parchment bindings were used frequently in the 16th and 17th centuries, and were sometimes gilt but were also often not embellished. In later centuries vellum has been more commonly used like leather, that is, as the covering for stiff board bindings. Vellum can be stained virtually any color but seldom is, as a great part of its beauty and appeal rests in its faint grain and hair markings, as well as its warmth and simplicity. Lasting in excess of 1,000 years—for example, Pastoral Care (Troyes, Bibliothèque Municipale, MS 504), dates from about 600 and is in excellent condition—animal vellum can be far more durable than paper. For this