We can discuss at length the unique properties of shell cordovan leather, why it is not technically considered leather from a scientific standpoint, and how its tanning process is lengthy and labor-intensive. However, first and foremost, we're talking about leather. That means, like any other leather, we need to tan and treat it with oils. This will be the focus of the text.

When I was preparing to write this text, I imagined the vast variety of materials used for tanning and greasing leather, and I was overwhelmed. I realized I couldn't possibly cover them even in ten articles like this one. But I decided to focus on why and what we use.

The answer to the first question is quite simple: we don't use materials that we couldn't either consume or apply to our own skin. Our product is alive, and it interacts with your skin every day. This means it shouldn't contain anything that could cause allergies or pose any level of risk to your health.

As a result of the first tanning process, we obtain a semi-finished product that already has the appearance and properties of leather, is stable, and ready for further processing (photo above). It's worth mentioning that tannins are rarely used individually but more commonly in a blend of several extracts, each with specific properties such as water solubility, tanning speed, acidity, and imparting various properties to the leather, such as density, strength, softness, color, and others.

Below, you can find information about tannins from books on leather production from the beginning of the last century.