The reason for the softness of leather is that the oil is introduced into the interior of the animal skin during tanning. This creates an oil film that covers the fibres inside the hide, i.e. between the surfaces of the fibres inside the hide, separated by a suitable thickness of oil film. The friction moving between the fibres inside the leather is equivalent to the friction of the oil molecules and the leather is therefore soft. When the oil inside the leather is depleted, the leather may become hard, discoloured etc. In order to make the leather products have a longer service life, we can clean and maintain it frequently.
The first thing we should do is clean the leather. Use a soft towel, dampened with water and wrung out, to wipe the leather repeatedly, then wipe it again with a dry cloth and leave it to dry in an airy place.
A moderate amount of petroleum jelly will maintain the leather. petroleum jelly is a semi-liquid mixture of alkanes or saturated hydrocarbons, also known as mineral grease, produced by the fractional distillation of petroleum. Its state is between solid and liquid at room temperature and is available in brown, yellow and white colours depending on the application. Natural petroleum jelly is obtained from concentrated residual petroleum oils such as alkyl hydrocarbon heavy oils; artificial petroleum jelly is obtained from a mixture of mineral oils thickened with pure ground wax or paraffin or paraffin grease. Petroleum jelly has a mineral oil odour, but no paraffin odour. It can be used as a raw material for medicines and cosmetics, as well as for lubricating machinery.
Wipe the surface of the leather with a clean soft cloth, using a little petroleum jelly (or a special oil for leather), to maintain a good ‘skin’ and avoid cracking, as well as to provide a basic waterproofing effect.
It is important to note that too much petroleum jelly can be devastating to the leather. High-grade leather is rich in pores and breathable, so when we use petroleum jelly, it will all be absorbed into the skin. If we use too much, it fills the pores of the leather fibres, destroying the simulated oil film in the leather, and the leather becomes hard, wrinkled, cracked and peeling. This is why it is important not to apply too much petroleum jelly or maintenance oil.