Kendra the Leathercrafter

Used with the kind permission of Kendra Hollyoak

Greetings, everyone! I'll be talking about parchment today...

Before the use of paper became widespread, in the 16th century, parchment was the most common writing material in medieval Europe. Stored under the right conditions (kept away from moisture and extremes of temperature), parchment is extremely durable and can last for over a thousand years (Reed 1972: 119).

Parchment is made from the untanned skins of animals (most often, cows, sheep, and goats). Parchment differs from leather both in its manner of production and in its physical characteristics. Leather owes its characteristics to the chemical alteration of the skin (by introducing tannins, oxidized-oils, or mineral salts), whereas parchment is made by physically altering the structure skin fibers.

In order to understand the nature of parchment, one must first know something about the structure of skin. Skin is composed of two main layers (a thin outer layer called the epidermis, and a thicker inner layer called the dermis or corium). The dermis is mainly composed of a spongy network of collagen fibers.

Hairs grow in depressions in the epidermis called follicles. The follicles are partially enclosed by the papillary layer of the dermis. The papillary layer, with its pattern of bumps, produces the distinctive grains in leather and parchment made from the skins of different animals (Ryder: 393).

When talking about leather and parchment, the term flesh side refers to the inside layer of the skin (the side connected to the animal), and the term grain side refers to the outer surface of the skin.

Although parchment-making involves many steps and unique processes, the most important step is the stretching and drying of the skin under tension. This is the step that determines the characteristics of parchment.

Parchment is made from the dermis of an animal. Stretching the skin, and working the skin while it is stretched, causes the dermal fibers, whose normal structure is a three dimensional net, to break down and realign into flat layers lying parallel to the grain and flesh surfaces of the skin.

Drying the skin under tension fixes the flattened structure of the dermal fibers so they cannot go back to their natural condition. If parchment gets wet and isn't kept under tension, it goes back to its original condition and essentially becomes rawhide.

The technique of parchment making in the medieval period isn't substantially different from the techniques used today (with the exception that some steps have been mechanized). Medieval parchmenters had an intimate knowledge of their craft and their materials. Although they may not have understood exactly why their techniques worked (the minute physical and chemical alterations caused by certain treatments), they knew what treatments produced desired effects and what variables could harm their results. This experience, coupled with the daily, hands-on practice of their craft, produced parchments unequaled by today's parchmenters.

The techniques of parchment-making were well-known and well-documented in the medieval period. One of the first descriptions of parchment-making is given in a Wattenbach manuscript of the 8th century. This source states that the skin was placed three days in lime water to loosen the hairs, which were then scraped off with a knife. Powdered chalk was rubbed into the skin during drying (Ryder:395).

In the early 12th century, Theophilus provided one of the best written accounts of medieval parchment-making (Reed 1972: 133-135):

The following sections detail the steps involved in parchment making:

1. Soaking

Soak the skin in repeated baths of clean water. Soaking cleans the skin and facilitates the absorption of the lime solution during unhairing.

2. Unhairing

Unhair the skin by soaking it in an acid or lime (alkali) bath to loosen the hair and the epidermal layer. Then remove the hair and epidermal layer by scraping (also known as pulling) with a blunt knife. Although acid baths were common in other parts of the world (mideast), in medieval Europe, soaking in a bath of slaked lime (Ca[OH2]) was used for unhairing since the 8th century.

Soaking in a lime bath also cleans, loosens and swells the dermal fiber network (facilitating later realignment of the fibers). The swelling of the fibers permits the lime liquor to fully penetrate the skin and loosens and removes much fatty material, liquid collagen, and ground substances (a sticky, mucus-like secretion interspersed with the dermal fibers).

In medieval times, unhairing was done over a curved beam with a two-handled, curve, blunt knife. After unhairing, the skin is returned to the lime bath to further swell the dermal fibers.

3. Fleshing

Use a sharp knife to further clean and level the flesh side of the skin by cutting away any hypodermal muscle and fat tissue still present. Like unhairing, fleshing was done over a curved beam but a very sharp, two-handled knife was used.

4. Washing

Wash and soak the skin in repeated baths of clean water to remove any remaining lime solution and reduce the pH level of the skin.

5. Stretching and Punching

Stretch the skin on a frame and work the flesh side with a lunar or semi-lunar knife. The working process is called punching and its purpose is threefold.

Punching: