Preparation

• The skin is prepared, usually by curing with salt, which soaks into the skin and stops the decomposition, giving the leather durability so that it can be worked with. Water is often added after this process to increase flexibility. Compounds such as lime are added and the leather is scraped, removing the hair and giving the surface of the skin the right texture. Although the leather is still stiff, preparation makes it ready for the primary leather making process, tanning.
  
  

Tanning

• When leather was first made, tanning was often done using vegetable-based chemicals, but mineral-based chemicals have come into common use. The goal is to complete the preservation process and leave the leather durable enough to be made into a variety of objects. Sometimes enzymes are used to soften the leather, but a mixture of salt and sulfuric acid is used as the primary tanning solution. Anti-bacterial chemicals are included to stop the growth of bacteria as the leather is soaking in the solution. A chromium solution is then used to restore flexibility and pH levels to the leather.
  
  

Finishing

• After the leather has been treated with chromium, it is finished to give it the proper commercial attributes. Some leathers are waxed or injected with oil to give them a shine and supply feeling. Other leathers are burnished or shaved to reach the desired thinness and texture. Many leathers are also dyed at this stage.
  
  

Chemical Cleaners

• Once leather products have been sold, they are treated with chemical processes to help clean and preserve them. There are two primary types of treatments used. One is a mixture of synthetic chemicals that include a light solvent or detergent that removes dirt from the leather. This also briefly darkens the leather as it penetrates the surface. Different kinds of chemical cleaners are made for different types of leather, such as full grain or suede.
  
  

Natural Oils

• Natural oils are the second option for leather treatment. This mixture is usually made out of beeswax and common oils that are designed to restore the leather's supply oil as it slowly dissipates. The mixture can protect the leather but can also change the texture over time.