Vellum

Terminology

In Europe, from Roman times, the term "vellum" was used for the best quality of prepared skin, regardless of the animal from which the hide was obtained, calf, sheep, and goat all being commonly used (other animals, including pig, deer, donkey, horse, or camel have been used). Although the term derives from the French for "calf", animal vellum can include hide from virtually any other mammal. The best quality, "uterine vellum", was said to be made from the skins of stillborn or unborn animals, although the term was also applied to fine quality skins made from young animals. There has long been, however, much blurring of the boundaries between these terms. In 1519, William Horman could write in his Vulgaria: "That stouffe that we wrytte upon, and is made of beestis skynnes, is somtyme called parchement, somtyme velem, somtyme abortyve, somtyme membraan." Writing in 1936, Lee Ustick explained that:

To-day the distinction, among collectors of manuscripts, is that vellum is a highly refined form of skin, parchment a cruder form, usually thick, harsh, less highly polished than vellum, but with no distinction between skin of calf, or sheep, or of goat.

Modern scholars and custodians increasingly use only the safe if confusing term "membrane". Depending on factors such as the method of preparation it may be very hard to determine the animal species involved (let alone its age) without using a laboratory, and the term avoids the need to distinguish between vellum and parchment.

French sources, closer to the original etymology, tend to define velin as from calf only, while the British Standards Institution defines parchment as made from the split skin of several species, and vellum from the unsplit skin. In the usage of modern practitioners of the artistic crafts of writing, illuminating, lettering, and bookbinding, "vellum" is normally reserved for calfskin, while any other skin is called "parchment".

Manufacture

Vellum is a translucent material produced from the skin, often split, of a young animal. The skin is washed with water and lime (Calcium hydroxide), but not together. It is then soaked in lime for several days to soften and remove the hair. Once clear, the two sides of the skin are distinct: the side facing inside the animal and the hair side. The "inside body side" of the skin is usually the lighter and more refined of the two. The hair follicles may be visible on the outer side, together with any scarring, made while the animal was alive. The membrane can also show the pattern of the animal's vein network called the "veining" of the sheet.

Any remaining hair is removed ("scudding") and the skin is dried by attaching it to a frame (a "herse"). The skin is attached at points around the circumference with cords; to prevent tearing, the maker wraps the area of the skin to which the cord is to be attached around a pebble (a "pippin"). The maker then uses a crescent shaped knife, (a "lunarium" or "lunellum"), to clean off any remaining hairs.

Once the skin is completely dry, it is thoroughly cleaned and processed into sheets. The number of sheets extracted from the piece of skin depends on the size of the skin and the given dimensions requested by the order. For example, the average calfskin can provide three and half medium sheets of writing material. This can be doubled when it is folded into two conjoint leaves, also known as a bifolium. Historians have found evidence of manuscripts where the scribe wrote down the medieval instructions now followed by modern membrane makers. The membrane is then rubbed with a round, flat object ("pouncing") to ensure that the ink would adhere well.

Preparing manuscripts

Once the vellum is prepared, traditionally a quire is formed of a group of several sheets. Raymond Clemens 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 ; 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 bind.

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—Gregory the Great, Pastoral Care (Troyes, Bibliothèque Municipale, MS 504), for example dates from about 600 and is in excellent condition—animal vellum can be far more durable than paper. For this reason, many important documents are written on animal vellum, such as diplomas. Referring to a diploma as a "sheepskin" alludes to the time when diplomas were written on vellum made from animal hides.

Modern usage

British Acts of Parliament are still printed on vellum for archival purposes, as are those of the Republic of Ireland. In February 2016, the UK House of Lords announced that legislation would be printed on archive paper instead of the traditional vellum from April 2016. However, Cabinet Office Minister Matthew Hancock intervened by agreeing to fund the continued use of vellum from the Cabinet Office budget.

Today, because of low demand and complicated manufacturing process, animal vellum is expensive and hard to find. The only UK company still producing traditional parchment and vellum is William Cowley (Est 1870) who are based in Newport Pagnell, Buckinghamshire. A modern imitation is made out of cotton. Known as paper vellum, this material is considerably cheaper than animal vellum and can be found in most art and drafting supply stores. Some brands of writing paper and other sorts of paper use the term "vellum" to suggest quality.

Vellum is still used for Jewish scrolls, of the Torah in particular, for luxury book-binding, memorial books, and for various documents in calligraphy. It is also used on instruments such as the banjo and the bodhran, although synthetic skins are also available for these instruments.

Paper vellum

Modern imitation or "paper vellum" is made from rag or plasticized cotton. Usually translucent, paper vellum in various sizes is often used in applications where tracing is required, such as architectural plans. It is more dimensionally stable than a linen or paper sheet, which is frequently critical in the development of large scaled drawings and plans such as blueprints. It was also extremely important in that reproduction technology for dissemination of the plans as, like a high quality natural vellum, it could be produced in a thin enough sheet to be virtually transparent to strong light enabling a source drawing to be used directly in the reproduction of field-used drawings.

Preservation

True vellum is typically stored in a stable environment with constant temperature and 30% (± 5%) relative humidity. If vellum is stored in an environment with less than 11% relative humidity, it becomes fragile, brittle, and susceptible to mechanical stresses; if it is stored in an environment with greater than 40% relative humidity, it becomes vulnerable to gelation and to mold or fungus growth. The optimal temperature for the preservation of vellum is 20 ± 1.5 °C (68 ± 2.7 °F).