Leather is a material made from the skin or hide of animals and chemically and mechanically treated to make it durable, pliable and no longer susceptible to putrefaction. Over time, the moisture in leather dries out. Heat also changes the structure of leather and makes it hard and brittle. Leather softeners or leather conditioners are used to make the leather softer and suppler and to extend the life of leather shoes. Leather softeners contain oils or fats that make the leather suppler, less susceptible to cracking, conditioned and shiny. The conditioning oils can be natural or synthetic and plant or animal-based.
Beeswax is used to condition, soften and waterproof leather. It is often mixed with other oils, such as orange oil, mineral oil or petroleum jelly to make a less viscous softener which is suitable for use in softening leather shoes. You spread a thin layer of the beeswax and oil combination over the leather and lightly rub the mixture into the leather with a soft cloth. You then completely buff the surface to a soft sheen. This makes the leather soft and supple and adds a water-repellent surface layer that helps to protect the leather from further damage.
Neatsfoot oil is an animal-based oil that is derived from the feet of cattle. It is used to soften leather shoes and other leather items. It restores sheen and suppleness to hard leather and rehydrates dried-out, brittle leather. It is known to darken some leathers and is not suitable for use on suede or napped leather finishes. Neatsfoot oil is used straight as a leather softener, or can be blended with other oils and ingredients for added benefits such as waterproofing.
Mineral oil is a light oil made from a non-animal or vegetable source, usually petroleum or other fossil fuel. It is used to soften and condition leather and can be used in its pure state or blended with other softeners. It is often combined with beeswax to make a softer, more fluid leather conditioner and to improve the ease of application of beeswax to the leather.
Mink oil is derived from animal sources. It is used to soften and condition leather as the natural oil closely resembles the oils found in animal skins and easily restores suppleness to the leather. Mink oil is often blended with pine pitch for leather softening. The pine pitch acts as a preservative and a fragrance, while helping to add a waterproofing layer over the leather. Mink oil is combined with beeswax when a stronger amount of waterproofing is needed along with the softening of the leather.