How Leather Tanning Works
Tanning leather is a process steeped in mystery to most but is essentially a balancing act between heat, time, chemicals and movement.
The Yu Mei family recently went on a field trip to the seaside town of Timaru to learn more about how the process of tanning leather works and this is what we discovered.
The raw deer skins arrive at the tannery, covered in a thick fur coat; the heavier the coat the softer the leather. The deer skins we use are a byproduct of the NZ venison industry and NZLL (New Zealand Light Leathers) work exclusively with registered NZ deer farmers for this reason.
Upon arrival hides are salted, this is important to both cure and dry out the hides. To further cure and remove the hair the skins they are soaked and limed. As deer skins are softer than cow this is done exclusively by hand. The fur is then sold on to other companies, decreasing waste. Soaking the skins also preserves all of the natural characteristics of the leathers.
At this point, the skins look like pale blue blankets and are called wet blues. This is when they go through their first grading, which is initially done by spotting any surface marks on the hides.
The second grading process is done by a computer which can pick up even the smallest mark on the skin. We use the highest grade, with minimal abrasions, but as it is a natural product there are always unique characteristics to each hide.
As all leather products require different qualities they are split to their desired thickness. For leather handbags, we want a durable leather that still has a soft handle.
Dying leather is another process that is equal parts science and art. Dye has to be measured exactly using a laboratory grade scale. Perfecting the colour is a process of trial and error, adding half a gram of dye can completely change the final colour. They are spun initially in the testing phase in small round washing machines, this is upscaled to specially made giant
wooden barrels when batch dying large amounts of leather.
The dyed leathers are passed through a dryer for up to five hours. At this stage the deer nappa is flat in texture and is gently tumble milled to bring back it's unique grain.
Lastly, the leathers are finished, and this is different for every order. By the end of the process, the premium leathers have passed through 35 sets of hands, and have been turned from skin that would otherwise be waste, into beautiful, buttery deer nappa.