Synthetic tanned

Synthetic tanning is frequently used as an alternative to chrome tanning.

Synthetic tanning agents (aromatic syntans) are produced artificially by man, so have no counterpart in nature. Examples of these include formaldehyde, glutaraldehyde (also known as glutaraldehyde), phenols and acrylates. Synthetic tanning method is not employed as an isolated tanning process, but mostly in a combination tanning process with either chrome tanning or vegetable tanning processes. Chrome leather production ensures retanning with synthetic tanning agents as they provide the necessary “fullness" to the leather. It is estimated that annual production of synthetic tanning agents amount to 200,000 tonnes (2008).

After tanning, when the leather is still wet and not dyed, it gets a bright colour and hence is also referred to as wet white.

Synthetic tanning agents - Wet white

A disadvantage of chrome-free (FOC) synthetic tanned leather is the sensitivity to moisture in the leather plus heat. Approx. 50% of all car leather is FOC. If a convertible comes into the rain, a liquid runs out or a wet towel or a wet swim suit remains too long on the leather, moisture migrates through the finish, the seam holes or the perforation holes. If sun shines on such wet leather, the matrix water (chemically bound in leather) starts boiling and the leather hardens and shrinks.