The Leather Tanning Process

Making leather is a complicated process. The tanning process involves five different stages: Pre-Tanning, Tanning, Selecting, Dressing and Finishing. Each of these processes is complex and requires many steps. Here is an overview of some of the more important points in each step.

Step 1: Pre-Tanning

Soaking

When the leather reaches the tannery, it can be soaked to squeeze out the salt used to preserve the leather. Washing in water to remove impurities and folds from the hides. This is done in a rotating drum that can hold up to 200 hides.

Pressing

The pressing process is to eliminate excess water and stretch the hides.

Splitting

The grain-the outer surface of the hide-is mechanically separated horizontally from the split.

STEP 2: Tanning

This is the process of converting pre-tanned leather into leather.

Common tanning methods include mineral tanning, vegetable tanning, synthetic tanning, oil tanning, combination tanning, etc.

STEP 3: Selecting

After the tanning step, excess water is removed from the leather. The leathers are then graded according to the natural characteristics and flaws.

At BONZ, each aviator jacket requires an average of 30 lambskins, because each skin is unique, our staff need to sort through 800 skins per batch to find the 30 BONZ jackets hidden in it.

Step 4: Dressing

Leather dressing includes the following steps:

Shaving

The entire surface of the hide acquires a uniform thickness.

Dyeing

The key point in the process, lending the hide softness, colour and stability.

Drying

Removing the water via vacuum suction using special equipment made of steel plates.

Trimming

Cutting, selecting and dividing the hide.

Step 5: Finishing

The purpose of finishing is to improve the overall performance of the leather, and to protect the leather from wetting and soiling, to minimize the appearance of grain blemishes without losing the natural beauty of the leather product. Further modify the surface properties (gloss, shadow, etc.).