Even the commoner kind of parchment used for official documents was rather a costly thing. The roll with the Visitation expenses of Bishop Swinfield, Bishop of Hereford from 1282 to 1317, shows that 150 sheets of parchment cost 3_s._ 4_d._, about £4 in modern value[240]. The vellum used for manuscripts has a different texture on its two sides. One side, that on which the hair grew, has a _mat_, unglossy surface; the other (interior) side of the skin is perfectly smooth and, in the case of the finest vellum, has a beautifully glossy texture like that of polished ivory. In writing a manuscript the scribe was careful to arrange his pages so that two glossy and two dull pages came opposite each other[241]. _Bad modern vellum._ The art of preparing vellum of the finest kind is now lost; the vellum made in England is usually spoilt first by rubbing down the surface to make it unnaturally even, and then by loading it with a sort of priming of plaster and white lead, very much like the paper of a cheap memorandum book. The best modern _vellum_ is still made in Italy, especially in Rome. Good, stout, undoctored vellum of a fine, pure colour can be procured in Rome, though in limited quantities, and at a high price[242], but nothing is now made which resembles either the finest ivory-textured vellum of fifteenth century Italian manuscripts, or the exquisitely thin uterine vellum of the Anglo-Norman Bibles. _Use of paper._ _Paper[243]._ Though by far the majority of the illuminated manuscripts of the Middle Ages are written on vellum, yet paper was occasionally used, long before the fifteenth century, when its manufacture was largely developed to supply the demand created by the invention of printing. Paper made from the papyrus pith has been already described, see Chap. II. page 22. _Mode of making paper._ A very different process was used for the various kinds of paper which were made in mediaeval and modern times. The essence of the process consists in making a fine pulp of cotton or linen rags by long-continued pounding with water sufficient to give the mixture the consistency of thick cream. A handful of this fluid pulp is then spread evenly and thinly over the bottom of a fine wire sieve, through which the superfluous water drains away, leaving a thin, soft mass which is then turned out of the sieve, pressed, dried and finally soaked with size to make the paper fit to write on. This process leaves the wire-marks of the sieve indelibly printed on to the paper. These marks are of two kinds, _first_, those of the stouter wires which run longitudinally along the sieve at intervals of about an inch or a little more, and _secondly_, very fine cross wires, placed close together, and woven in at right angles to the first-mentioned stouter wires. _Water-marks._