All of the sellers of conditioners will, of course, hawk their own wares, e.g.,

Leather Conditioning Explained: http://www.properautocare.com/leclcoex.html

A candid interview with Dr. Don Jenkins and Phil Meyers from Summit Industries

Proper Leather Conditioning

Q. What is leather conditioning?
A. Conditioning replaces the natural tanning oils evaporating out of the hide. The smell of leather comes from these oils. If not replaced, leather will eventually dry out, become brittle and crack. Think of these tanning oils as microscopic, lubricating oils. If you look at leather under a microscope, the fibers look like a pile of rope that's all tangled up. Tanning oils coat these fibers allowing them to bend, move and slip across one another. These oils keep the leather soft and supple. Without lubrication, leather fibers will become stiff and brittle. When repeatedly flexed, stiff, dry fibers will simply break and the leather will develop cracks.

Q. That sounds simple enough. So what makes a good tanning oil or lubricant for conditioning leather?
A. All cow hides are naturally oily. Unfortunately, these natural oils are stripped away in the tanning process (Tanning is the process that renders the hide invulnerable to decay.) and some equivalent oils must be re-introduced after tanning. This last tanning step, the replacement of oils, is called "fatliquoring." Over the centuries, a number of oils have been found that have a natural affinity for leather fibers. Every leather tanner has his own, unique, blend of tanning oils. These formulas are closely held secrets, passed down through the generations. This is one reason why one company's leather can have a totally different feel, fragrance, texture and softness from another company's product. Tanning oils can contain a variety of oils including Neatsfoot oil, Sperm Whale Oil, pressed lard and Lanolin.

Q. I've heard the term Neatsfoot oil. What is it? Where does it come from?
A. Neat is an archaic name for hooved animals (i.e. cows, pigs, sheep). Neatsfoot oil is oil rendered from the feet of cattle or hooved animals. In the slaughterhouse, the feet would be cut off the animal, split, put into a large vat and boiled. The oils that rose to the top would be skimmed off and sold as "Neatsfoot Oil." Today, thanks to the US military, there is no actual Neatsfoot oil in Neatsfoot Oil! Let me explain. Back in the 1930's the US Army wrote a Military Specification (Mil Spec) that defined the properties of Neatsfoot Oil. Oil merchants bidding for government contracts quickly discovered other, less expensive, oils would meet this Mil Spec. Today, Neatsfoot Oil is any oil, regardless of where it comes from, that meets this US Government Mil Spec. Neatsfoot Oil now is mostly derived from pigs. Lard is pressed and the resulting liquid, which can be supplemented with mineral oil and/or reclaimed motor oil, is sold as "Neatsfoot Oil". Neatsfoot oil is widely used in the equestrian industry (saddles and tack) but has no advantage in conditioning the finished leathers found in automobiles.

Q. You make both Lexol Leather Conditioner and Lexol NF Neatsfoot Oil. Which should I use ...



I can recommend this from personal experience:

Mink oil
From Wikipedia, the free encyclopedia

Mink oil is made from the thick fatty layer minks have just under their skins. This fat is removed from the pelt when the mink is skinned and is then rendered into mink oil. Mink oil is a source of palmitoleic acid which possesses physical properties similar to human sebum, therefore mink oil is used in several medical and cosmetic products. Mink oil is also favored for treating and preserving leather.

Botanical alternatives to mink oil as a source of palmitoleic acid include macadamia nut oil (Macadamia integrifolia) and Sea Buckthorn oil (Hippophae rhamnoides), both of which contain a larger percentage of palmitoleic acid (22 and 40% respectively) than does mink oil (17%).

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