What it is parchment?

Parchment is a living material, obtained from raw animals skins, without limitation of species, but most usually used are the skins of ovine races, goats and cattle.

Examples Lamb Parchment, Salmon Parchment, Goat Parchment

Among the skins of cattle, most appreciated are the ones from the still-born calves which give a very fine parchment, called vellum.

After processing of the raw skins, there is only the dermis, which has a smooth appearance, more or less white, more or less translucent, of thickness from 0,1 to 3,5 mm depending of the species and the age of the animal, and which has very good solidity.

However, we can still distinguish on one hand, the external part of the animal, by the imprint left by the presence of hairs, which is characteristic of the species and on the other hand, the inside which is always more softer and clearer than the other one (the collagen fibers are less tightened there).

It is common to hear that parchment is tanned or semi tanned. That's not the case, because if we consider the definition of the tanning, operation consists in fixing molecules of tannins to that of the dermis; during the manufacturing of parchment, the skin is never in touch with tannins. The exact term is to say that the skin is given a parchment finish, which is not irreversible because we can wet again a parchment and tan it to make it into leather.

On the other hand, we all have heard of paper called “vellum” paper. These terms are used in the ordinary language to indicate quality papers, but the parchment is a product only obtained from animal material. Also, we find materials called parchment or plant parchment, which copy the veined aspect or the transparency but which are in fact paper or paper traces.

USE OF the PARCHMENT - DATA SHEET

Parchment is constituted of the dermis of the skin. Similar to some leather, its properties however differ.

Aspect
To the touch, parchment is smoother and softer on the outside side than on the inner side.
Its natural color depends on the color of the animal and can vary from white to crem, but also from chestnut to black.
The thickness depends on the nature and on the age of the animal and can vary between 0.1 and 3.5 mm. Naturally translucent, it lets light through.

Resistance
In equal thicknesses, it is far more solid than paper. It is almost impossible to tear it, unless it contains a cut.

Temperature
Warmed by flame, used dry, it curls up irreversibly. Warmed in water, it can turn into glue.

Hygrometry
The wet parchment becomes soft and takes some thickness.
It can be useful to sheathe objects, the shape of which it will take in the drying, on the condition of being maintained by staples, some glue or a sewing
Parchment is thus sensitive to the hygrometric variations. Used dry at first, it tends to crinkle strongly if it is not maintained.

Sticking
The recommended glue is the vinyl glue or the white glue.
Certain craftsmen insert some tissue or some paper (stuck or not) between the medium and the parchment, either to favor the sticking, or to unify the bottom.

Processings
Parchment can be colored, printed, sanded it to thin it, polished or varnished…