LEATHER IN GENERAL
Although the manufacture of leather belongs to one of man’s oldest professions and leather and skins have been used by man for dressing purposes from time immemorial, only a small number of people, outside the trade, know anything in particular about leather.
Leather:
It is the ordinary designation of tanned hides and skins.
Tannage:
Causes the hide to keep its original structure and not to be damaged by water or putrefactive bacteria. The TANNING may be done in various ways according to the purposes of the leather. The most important tanning methods are the following:
- Chromium Tanning: Made with chromium salts.
- Vegetable Tanning: Made with extracts of weed bark and plants (oak, pomegranate bark, chestnut, mimosa, etc…
- Made with tanning agents based on coal and mineral oil.
Chamoising:
(Wash-leather tanning) is made with whale oil.
The above tanning methods can be combined – e.g.: to give the leather a certain character or quality. This is called combination tanning. During the tanning process, the lubrication of the leather takes place too, made with various kinds of oils to make the leather soft and supple and perhaps waterproof.
The dyeing of the leather can be divided into 2 main groups:
- ANILINE DYEING
- PIGMENT DYEING
Aniline Dying:
Normally aniline dyeing is made in water baths (with dye known from textile dyeing) which gives a good through dyeing of the leather. The through dyeing means that the bright color of the leather itself will not show after wear and tear or scratches when in use and that the aniline dyed leather, apart from possible fading, will keep its original color. However, aniline dyes often set off grain faults in the hides and the dyeing might appear stained. It can also be difficult to make the various dyeing uniforms. However, aniline dyes gives the leather certain vitality and the grain marking remain open and natural. Not all-aniline dyes are of the same fastness to light; pure aniline dyed leather will often change in strong daylight. The finish that we put on our fully aniline dyed leather is mainly done in order to:
- Give the leather the shade wanted;
- Correct and level/balance the varying aniline dyeing;
- Give the leather a uniform surface, which is waterproof and resistant against grease, dirt, etc.
- Cover small blemishes;
- Give the leather a certain sheen, non-gloss or glossy;
- Enhance the light fastness of the leather
Pigment dyeing:
Pigments also called opaque colors, constitute a “paint” especially composed for leather and are applied on the basis of various kinds of binders. Today plastic, casein and cellulose lacquer is mostly used.
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Leather Care