Leather

Pile of leather

Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hogs, and aquatic animals such as seals and alligators. Leather can be used to make a variety of items, including clothing, footwear, handbags, furniture, tools and sports equipment, and lasts for decades. Leather making has been practiced for more than 7,000 years.

Production

Tanning is the broad name for the process done to rawhide to convert it into usable leather that is resistant to decay and putrefaction.

Preparation

Before rawhide can be tanned, it must first be scraped and cleaned to remove all the hairs, and any remaining meat, fat, or connective tissue from the rawhide. Then they are cured to prevent putrefaction, either in a sealed vessel filled with salt for a 30 days, or agitated in a brine for 16 hours.

Beamhouse Operations

Beamhouse operations are the collective steps performed between preparation and tanning. In order, they are soaking, liming and scudding, deliming, and pickling

Soaking

First, soak the hide in water to wash any excess salt.

Liming

Next, soak the hide in slaked lime. The ratio should be (I couldn't find a ratio. I only saw a ratio of about 1 pound quicklime to 10 gallons water, but that's not a clean conversion). This is done to break down any leftover hairs or fats on the hide, as well as open up the collagen to better let in tannins. Any hairs remaining after liming are removed by scraping the hide with a dull knife in a process known as scudding.

Deliming

The hide is then soaked in a mixture of water, and an acid that can be rapid in their pH adjustment.

Pickling

Despite the name, this step has nothing to do with the food preservation process of the same name.

For the final step, the hide is soaked in a solution containing tannins for a period of two to three months, after which it is dried and ready for use.

Plants with High Tannin Content

Hardwoods

Hardwoods are a significant source of natural tannins. Woods with high tannin content can be identified by typically having a darker brown coloration, as well as the signature bitter, astringent, drying taste, the same as in acorns. For all of these species, large amounts of tannins can be found in the wood, bark, and leaves.

Wood Species Name	Wood Coloration	Tannin Content	Ext. Notes
Oak	Light Brown
Chestnut	Light Reddish-Brown
Quebracho	Dark Reddish-Brown
Acacia	Orange Brown

Other

While most prominently in hardwood, tannins can be sourced from other plants as well.

Other	Tannin Content	Ext. Notes
Pomegranite Peel
Tara Pod

See also

• Cotton
• Linen
• Nylon
• Silk
• Rawhide
• Raw material
• Wool
• Textiles

References

This article uses material from the Wikipedia article Leather, which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).