Regardless of the animal in question, raw leather must be treated to preserve it and make it suitably soft and durable for use as a material in a variety of products. This process is called tanning and there are numerous different tanning methods.
Vegetable tanning, which usually uses broth extracted from the bark or wood, is a thousands-year-old leather-making process that has been used primarily to produce bovine and other hides and skins prior to the development of chemical tanning agents and methods. Vegetable tanning gives the leather a brown tone and a genuine leather scent. For example, leather tanned with willow bark, which was commonly used for tanning in Finland, will still be recognized after decades as tanned with willow. Chemical tanning is popular because it has a fast manufacturing process and makes the leather more heat-resistant and easier to dye. However, the most prestigious leathers are still made with traditional vegetable tanning.
Vegetable tanning is also a good method for making fish skin leather. It makes the leather strong, durable and, if necessary, soft. Fish scales are removed during tanning (just like mammals are depilated), the scale pockets left on the skin form a recognizable pattern on the surface, for example with salmon leather.
The smooth Burbot leather is very comparable in properties to thin sheepskin or reindeer leather.Fish skin leather is thinner than commonly used mammalian skins, but in relation to thickness it can be even stronger. For example, a 2.5 mm wide strip of burbot leather overcomes the tensile strength of a reindeer leather strip of a similar width but thicker. Good examples of durability are wallets with a completely fish leather surface. It is not uncommon for these wallets to have a lifespan of more than 10 years. So, the fish skin leather is strong and durable and can withstand a wide range of uses.
One of the most important steps in manufacturing is the thorough cleaning of the leather in the initial stages. It involves removing the fish's own fat from the skin, so that the "fish smell" is no longer present in the finished leather. Thus, a well-made fish skin does not smell like fish, but it has the scent of wood used as a tanning agent.
Fish skin leather is not just a decorative material, it can be used like any other leather in various wear-resistant items. Wallets, belts and coin purses are good examples of this. Fish skin has also been used in shoes and clothing. The biggest technical factor limiting the use of fish skin leather is the size of the fish skins. Fish skin leather can be used to make large surfaces, but it requires a lot of individual skins and seams. Fish skin leather is sewn and glued as with other skins.
Ready-made fish skin leathers are scarcely available in comparison with mammalian leathers and, moreover, manufacturers are few and operators small. Fish skin leather is also more expensive than mammal's leather of the same size. In many products, the small size requires the sewing of multiple leather pieces and good design to minimize the waste of material.
Very different fish skin leathers are obtained from different species of fish and the quality of leathers varies from manufacturer to manufacturer. Prejudices about the smell and weakness of fish skin leather influence many people's decision not to use fish skin. You can easily get a false impression of fish skin leather if you have only seen the hard and rough leather made by an enthusiast with hard work.