Tanning is the process by which skins are turned into leather and is done in a tannery.
There are two main types of commercial tanning process; vegetable tanning and chrome tanning.
Vegetable tanning is a very old method. It involves soaking the prepared skins in containers with solutions containing bark and leaves over a period of one to three months.
The majority of leather is tanned using the more recently developed chrome tanning process. The prepared hides are soaked in acidic salts and then in chromium agents. It is a much quicker process than vegetable tanning; typically only one day.
Types of Leather
Full Grain Leather
Full grain leather has not been split or had any abrading or sanding done to the outer surface so you can see any imperfections that may be present. This is a good thing! This is the highest quality of hide and is most sought after for leather goods where strength and longevity are required.
Top Grain Leather
Sometimes full grain leather is split horizontally into several layers. The top-most layer is called top grain leather. It looks like full grain leather but is not as thick or strong.
This is the portion of the hide that remains once the top grain has been split off. These layers can be embossed to make them more visually appealing. This part of the hide is softer and more malleable than the top grain and is often used in bag making. This type of leather is sometimes called ‘genuine leather’. Suede is one of the splits. It is used for apparel, bags and shoes.
Bicast leather has two layers. The bottom layer is a split leather backing and this is covered with a layer of polyurethane or vinyl which is embossed to look like leather. It is used in furniture making.
This is real leather but is of a lower quality than full grain or top grain leather. It is often made with several layers of split leather bonded together and finished to look like full grain leather. Used in lower quality shoes, bags and belts.
This product is made of finely ground-up scrap leather mixed with polyurethane to bond it into a sheet. Used in furniture making.
PU stands for ‘polyurethane’. PU leather is therefore made of a type of plastic that is made to resemble leather but does not contain any leather. It can be found in furniture and shoe making and is a cheaper alternative to real leather.