Leather is a natural material created through the tanning of hides and skins of animals- most commonly cattle/cow hides. Leather can come from numerous types of animals- including: snakes, alligator, and shark- however, common practice is to be paired with the dairy/meat industry and use the by-products of the cattle already being used. Hides come from across the world and vary according to location due to temperature (the thickness), feed (size of cattle), and where they were raised (wood vs. barbed wire fences affect their hide imperfections).
Leather is cleanable, repairable, breathable and has different textures and grades. Each hide is unique to the animal, but can be treated to be identical for certain purposes.
Let's start at the beginning:
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| Diagram of Leather Grains |
Full Grain- Upper section of hide that contains the skin layer and all the imperfections. Only hair has been removed. It is considered the highest quality and instead of wearing out, it will develop a natural patina. It has the highest durability and can be bought as either aniline or semi-aniline. Nothing is done to correct it.
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| Full Grain shown on a bag..."bomber jacket" look |
Top Grain- Top grain leather has often been buffed or sanded to remove scars. This pigmented leather is the top portion of the split hide. The original grain can be removed and the surface is sanded and refinished to produce a consistent grain pattern. In some cases, the surface is only lightly buffed and refinished.
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| Top Grain- high quality and only slightly corrected |
Corrected Grain- Top grain leather that has been sanded and buffed to remove any imperfections due to bug bites, scars and brands. It will be embossed or printed and can be finished as semi-aniline or pigmented.
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| Corrected Grain- Rid of scars, markings and very "perfect" looking. |
Split- Made from the bottom part of the hide. It will have an artificial layer applied to the surface and will be embossed. It is typically used in lower priced furniture. Splits are used to create suede.
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| Suede: Low quality but perfect for the right look! |
Bonded Leather- This is a man-made material composed of leather fibers and latex binders. It can create a look similar to leather at a fraction of the cost but is less durable and not recommended on furniture.
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| Bonded Leather- lowest quality-seen on less expensive furniture (think: discount furniture shops) |
How is it made?
1: Pre-Tanning
Soaking - When the leather arrives at the tannery it may be soaked to extrude salts used in preserving leather. This is done in revolving drums which can hold up to 200 hides.
Liming - Hair and epidermis are removed and a solution of lime (calcium hydroxide) and sodium sulphide is applied to soften and enhance hide for softness and flexibility needed for upholstery leather.
Splitting - The hide is split into layers. The top, or grain, layer will produce a fine, smooth grain leather. The bottom is used for suede or split leather for other uses.
2. Tanning Process: This converts the skin/hide into a durable, long-lasting and versatile material.
The 2 most common processes are:
Vegetable Tanning: This is a more environmentally sound process because of the lack of chemicals.
It uses tannin and ingredients found in vegetable matter and tree bark. It can discolor and harden when wet. This is better for "natural" colors.
Chromium Tanning: This is the most common method and uses chromium sulfate and salts of chromium. This stabilizes the leather and making it more pliable and supple than vegetable tanned. It will not discolor or lose shape. This process allows for more "vibrant" colors.
3. Selecting: After tanning excess water is removed from hide. Hides are then graded according to the quantity and locations of natural features and flaws. Top, Full and Corrected Grain leathers demand the best quality hides. Heavily coated or embossed leather can utilize a lesser quality of hides.
4: Dressing: This involves different steps shown below:
Shaving - Hides are given a uniform thickness; Dyeing - Dyes are added to color leather. (See below)
Re-tanning - Additional tanning substances are sometimes added to modify the physical characteristics of the leather to suit its final use.
Setting - A process which mechanically removes creases and excess water.
Drying - The hides are stretched dried on large frames or vacuum dried.
Trimming- The rough and ragged edges are removed.
5: Finishing: This is the stage to give the required degree of gloss, ensure the leather is soft, malleable and moldable, to give a more protective surface which is easily cleaned.
6. Embossing: This adds pattern to the leather to hide the unwanted characteristics and create visual appeal. (Not always done.)
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| An example of embossing. |
7. Protecting the hide: Topical applications to protect the surface.
Dying Differences
Aniline: This is a bi-product of the petroleum industry. Pigments are added to achieve the desired color. Then they are mixed with the hides to color them.
Full Aniline: Leather hides fully dyed using aniline dyes and then a layer of protection added to the top.
Semi- Aniline: Leather hides that are fully dyed first, then a color surface coat is applied.
What Should I Buy?
Hopefully after reading this article, you will feel more empowered on what to look for when buying leather. Key words: Full or Top Grain, (or Corrected IF that is the look you want!); Aniline Dyed; and/or Vegetable (if you are going GREEN). Steer clear of "Split- leather," and "Bonded leather." And ASK questions! That's why we are here!
Thanks for stopping by!
-Team CC
Sources:
American Leather
Keleen Leathers
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