New know-hows reconcile color and sustainability in leathers The 3 November 2022 - Leather - Colors

New techniques take full advantage of leather’s wide range of behaviors. By modifying parameters such as the pH and astringency, these techniques enhance leathers’ natural shades, while paving the way to more supple, less compact handles.

Soydan and Raynaud are both offering undyed Basane that retains the original color of the skins. Simple patinas and finishes play on the naturalness and authenticity of each skin, resulting in handles that are less firm.

France’s Ictyos specializes in marine leathers. The fish skins – salmon, sturgeon, trout – come from industrial waste. The DNA of Ictyos is rooted in local and traditional know-hows teamed with innovation. The company has developed a collection whose dyes are derived from agri-food waste. These polyphenol-rich dyes replace traditional dyes and enrich the palette with new shades.

Their Squama® Raw collection is made from bark from Quebracho and chestnut trees, and, for example, offers a variety of new beige tones. In addition, a collection developed thanks to grape marc proposes a range of soft wine-sediment hues.

Thanks to biopolymers, tanners have concocted vegetable recipes that allow for brighter, more luminous tones, moving away from the natural hues attributed to classic vegetable tanning-agents.

Such is the case at Olivenleder, which has developed a wet green process. Olive leaves from agri-food waste are transformed into active tanning agents. The result is a concentrated aqueous substance, free of metals and any chemical tanning agent. This new process improves color intensity when compared to traditional vegetable tanning.

Ecotan® from Silvateam is a new-generation vegetable tanning process whose technology teams vegetable tannins and biopolymers. This process results in round, supple leathers in deep, intense shades without the use of chromium or glutaraldehyde. Developed with partner tanneries and a fertilizer manufacturer, the quality and non-toxicity of its co-products make it possible to transform residues into biological fertilizer at the end of the life cycle.

The latest innovations include Zeology™, whose technology paves the way for pale or very intense colors that are light resistant.

This method is formulated with zeolite, a mineral that binds to the skin’s collagen to provide characteristics similar to chrome. Used by Nera Tanning, this tanning process is free of chrome, heavy metals, bisphenol A and glutaraldehyde. Both glutaraldehyde and bisphenol A, which are frequently used in synthetic tanning, have been included on the SVHC list of substances of very high concern. This process has obtained Cradle to Cradle platinum level of certification, and ZDHC level 3 certification, which is currently more restrictive than the Reach regulation.

To obtain a product that is biodegradable and compostable at the end of its life, a 360° approach is required. Such a virtuous circle requires a cleaner choice of dye, combined with a more sustainable finishing.

Using less pigmented dye will result in a more transparent colored finish, which has the added benefit of preserving the natural quality of the skin. The result is a more durable product with less surface wear.