Does leather conditioner clog pores?

I’ve heard some weird theories about leather care and maintenance. It recently came to my attention that there are people who believe that conditioners are bad for leather, as they “clog the pores”. I have no idea how they came up with their theory. Does it clog pores? What does that mean? Is the leather going to develop a “blackhead” or pimple due to clogged pores?

Here are the facts. Please note that the cow is dead. The pores are not functional. The animal no longer sweats. The animal does not produce more body oils. Nothing comes out of the inside of the skin through the pores. What is there to block?

Furthermore, a pore is just a structural element found in the topography of a skin. Observed under a microscope (even a simple magnifying glass) will show that the pore structure represents a small percentage of the total surface area. Leather is absorbent on its entire surface, not just in the pores.

If you put a large amount of a heavy, greasy substance as some leather conditioner manufacturers propose, the real problem is that the leather cannot absorb it. So it dries on the surface and leaves the leather with a tacky, sticky feeling (clogged pores?).

Consider the following:

1. Leather has a moisture content of around 25% coming out of the tannery.

2. That moisture evaporates into the atmosphere at a rate based on 3 variables: A) humidity B) temperature and C) skin porosity. (An unfinished leather will dry faster than a finished leather because it loses moisture at a faster rate since the natural surface of the leather is not coated. A finished leather has a coating that will retain moisture longer. In both cases , moisture is lost from the chamois side as well.) The heavier the finish, the slower the rate of moisture loss. The corollary is that a highly finished leather will be less absorbent of any wetting agents. If it’s slow to get out, then it’s also slow to get in.

3. As the leather loses moisture, the fiber bundles lose their internal lubrication and the leather becomes tougher. In addition, it loses a part of its mass, so it contracts.

4. The purpose of a conditioner is to restore lost moisture, improving flexibility and extending the life of the leather. Period.

5. Do not replenish moisture (do not apply conditioner) and it will surely shorten the life of the leather as it dries.

pH balance

What is much more important is to understand that leather is acidic (4.5 to 5.0 on a pH scale). A lot of harm is done by applying a chemistry that is not pH balanced on the leather, as it will induce a chemical reaction that breaks down (rots) the fiber structure. Consider body oil buildup – some people are very caustic (pH below 3.5) causing leather to fade. Advanced Leather Solutions cleaners and conditioners are pH balanced for leather, helping to correct any pH imbalances that combat the breakdown effect.

Museums use non-volatile humectants.

At the conservation and preservation (museum) level, it is true that a standard grade conditioner MAY do more harm than good. Once the leather reaches a certain level of moisture loss (estimated below 5-10%), adding a greasy conditioner at that point can cause the leather to soften. (Think cardboard when it gets wet.) Therefore, the goal is to ensure that the moisture content of the leather never drops to such a low level by regularly conditioning your fine leathers.

Most conditioners are made from organic products like ox foot oil, which are also the “natural oils” that are infused into the leather at the tannery. Organic compounds are volatile, which means they evaporate, which is the main reason why leather needs moisture added from time to time.

A non-volatile humectant is synthetic and does not evaporate. However, they are very expensive, so tanneries generally do not use them. Advanced Leather Solutions has developed a deep penetrating moisturizer that is a non-volatile conditioner. It is a highly specialized chemistry that acts like countless tiny ball bearings infused within the structure of the fiber. In that sense it is not a liquid (it does not evaporate). Once applied, you don’t have to continually hydrate as it is not lost to the atmosphere.