Between the animal and the artisan, there is a step that almost nobody talks about. It is unglamorous, technically demanding, and entirely invisible in the finished bag. It is also the reason your Winklmayr piece will still look magnificent in thirty years — or why a cheaper bag will not survive five. That step is tanning, and this is what actually happens inside a tannery.
When customers ask how a Winklmayr bag is made, the conversation almost always begins at the workshop: the pattern-cutting, the hand-stitching, the edge finishing. Occasionally it goes further back, to the farm and the hide itself. But the tannery — the place that transforms a raw animal skin into the extraordinary material that arrives at our atelier door — remains largely a mystery, even to people who care deeply about what they carry.
The images in this post are taken at Cape Karoo International (CKI) in Oudtshoorn — the world’s largest ostrich tannery, and the supplier behind every Winklmayr exotic leather piece. It deserves a closer look.
Why tanning exists at all
The problem tanning solves
A raw animal hide is, chemically speaking, a protein structure that will begin to decompose the moment it is separated from the living animal. Left untreated, it will rot, stiffen as it dries, crack, smell, and ultimately disintegrate. The challenge that human civilisations have been solving for thousands of years is: how do you stop that from happening?
The answer is tanning — a chemical process that permanently alters the protein structure of the hide, binding the collagen fibres in a way that prevents decomposition and gives the leather its characteristic softness, flexibility, and durability. The word itself comes from “tannin” — the naturally occurring plant compound that was the original tanning agent, and that is still used today in one of the two main methods.
Without tanning, there is no leather. There is only treated hide — which is something quite different, and something that would not survive the demands placed on a luxury handbag.
The large rotating tanning drums inside the Cape Karoo International facility in Oudtshoorn — it is inside these drums that raw ostrich hides are chemically transformed into leather.
“Tanning permanently alters the protein structure of the hide — it is the invisible chemistry that makes everything else possible.”
Stage by stage
What actually happens inside a tannery
The journey from raw skin to finished leather is long, physically demanding, and requires a level of chemical and material expertise that takes years to develop. For exotic skins — ostrich in particular — every stage is more specialised, more time-consuming, and less forgiving of error than for standard cowhide. Here is the full picture, as it happens at CKI in Oudtshoorn.
Raw hides arrive at the tannery already salted — a traditional preservation method that draws out moisture and prevents bacterial decomposition during transport. Each hide arrives with its provenance documentation: for exotic skins, this includes CITES permit numbers tracing the skin back to its certified farm of origin. The hides are inspected, sorted by size and quality grade, and stored until processing begins. CKI works with approximately 1,000 farmers across the Klein Karoo.
Duration: days to weeks in storageThe dried, salted hides are immersed in water to rehydrate them and remove salt, dirt, blood, and other surface impurities. The hides are agitated in large drums, with water changed repeatedly until the skin has fully rehydrated. For ostrich leather, this step requires careful monitoring: over-soaking can damage the distinctive quill follicle pattern; under-soaking leaves the hide too dry to process correctly.
Duration: 12–48 hoursThe rehydrated hide is immersed in an alkaline solution of calcium hydroxide (lime) and sodium sulphide. This chemically loosens the epidermis and outer protein layers, causing them to swell and separate. It also opens the collagen fibre structure, essential for tanning agents to penetrate properly. For ostrich leather, this stage must be handled with exceptional care — the quill follicles that define the leather’s distinctive appearance are vulnerable to damage, and a poorly managed lime bath can destroy the pattern that makes the skin valuable.
Duration: 1–3 daysThe loosened surface tissue is mechanically removed. The reverse side of the hide is then run through a fleshing machine, which removes subcutaneous fat, tissue, and remaining flesh. What emerges is called a “pelt” — a clean, bare hide stripped back to its pure collagen structure. For ostrich hides, the deep-rooted quill follicles require particularly precise calibration at this stage.
Duration: several hoursBating uses enzymes to relax the collagen structure further and remove residual non-collagen proteins, resulting in a softer pelt with better dye uptake. Pickling then adjusts the pH of the skin using a mild acid solution, preparing it chemically for the tanning agents. These preparation steps are critical — skipping or rushing them produces leather that is uneven, patchy, and far less durable in the long term.
Duration: several hours to 1 dayThe pelt is placed into one of CKI’s large rotating drums filled with tanning solution. The tanning agents penetrate the collagen fibres and chemically bond to them — permanently preventing decomposition and giving the leather its stability and flexibility. Chrome tanning is used for ostrich leather: it produces a softer, more supple result that allows the natural quill pattern to remain fully visible and tactile. The result at this stage is called “wet blue” — a pale blue-grey damp hide that is now, chemically, leather.
Duration: 1–3 days (chrome tanning)The wet blue hides are wrung out, shaved to a uniform thickness, and returned to the drum for re-tanning — which refines the leather’s properties further. Fat-liquoring follows: oils and fats are worked into the leather to lubricate the collagen fibres and ensure the leather remains supple rather than drying out and cracking with age. The hides are then stretched and pinned flat to dry — as seen in the images below — a critical step that must be done at the right tension and temperature to ensure the leather dries without distortion.
Duration: 2–5 days
Ostrich hides pinned flat and stretched across drying frames at CKI’s Oudtshoorn tannery. This step is critical — the tension applied during drying determines the final shape and consistency of each hide.
Dyeing takes place in smaller drums, where the leather is tumbled with dye solutions until colour penetrates uniformly throughout. CKI is recognised internationally as a pioneer in ostrich leather dyeing and finishing techniques, producing over 300 colours. For lighter shades, the process may include bleaching the natural pigmentation first to create a clean base before building colour in controlled stages. Depending on the target colour, dyeing can take several days to several weeks.
Duration: days to weeks, depending on colourFinishing gives the leather its final surface character. A series of treatments — applied by spraying, rolling, or hand — build the surface layer that protects the dye, determines the sheen (matte, semi-gloss, or high-gloss), and affects the final feel of the material. CKI produces a range of finishes including Classic, Saddle, Nappa, Metallic, and Printed — each suited to different applications and design aesthetics. The leather is graded once more after finishing, and only what passes quality inspection leaves for the atelier.
Duration: 1–3 days
The method behind the material
Chrome tanning vs. vegetable tanning: what the difference actually means
If you spend any time in the world of leather, you will encounter strong opinions about tanning methods. Here is an honest account of what the differences actually mean for a finished bag.
Chrome tanning produces a softer, more supple result that allows the natural surface texture of ostrich leather — its quill follicle pattern — to remain fully expressive. Vegetable tanning’s firmer result tends to flatten these features. For a bag where the material itself is the defining aesthetic element, chrome tanning consistently produces the superior outcome. The two methods are not in competition — they serve different materials and different purposes equally well.
Modern Italian-engineered tanning and dyeing drums at CKI’s Oudtshoorn facility. Each drum slowly rotates for hours or days, ensuring complete and uniform penetration of tanning agents and dyes throughout the hide.
“CKI is recognised internationally as a pioneer in ostrich leather dyeing and finishing — the largest ostrich tannery in the world, and the supplier behind every Winklmayr piece.”
Why this matters to you
What the tannery’s work means for the bag you carry
Understanding tanning changes how you relate to a leather bag — because it reveals that the material itself is the result of months of skilled work before a single stitch has been made. A hide that has been properly soaked, limed, bated, pickled, tanned, re-tanned, fat-liquored, dyed, and finished at a facility like CKI is a fundamentally different material to one that has been rushed through any of those stages at a lesser operation.
This is one of the reasons cheaper leather bags begin to crack, peel, or stiffen after a few years of use. It is not always about the quality of the animal skin. It is about what happened between the farm and the workshop. Poor tanning produces poor leather, regardless of the skin’s origin.
CKI has been tanning ostrich leather at the Oudtshoorn facility since 1970 — over fifty years of accumulated knowledge, refinement, and innovation. They hold ISO 14001 environmental certification, Leather Working Group (LWG) accreditation, and CITES compliance across their entire supply chain. When Winklmayr chooses CKI as our supplier, it is a choice made not for convenience, but because their standard is the one our bags require.
The next time you run your hand across a Winklmayr bag — and feel the particular softness of the ostrich leather, or notice how the quill pattern catches the light — you are feeling the result of a process that began weeks before the bag was designed, in a facility in the Klein Karoo that has spent more than half a century perfecting it.
We think that is worth knowing. Explore the full collection at the link below, or write to us at info@winklmayr.com with any questions about our materials or sourcing.
Handcrafted in South Africa • CKI ostrich leather, Oudtshoorn • Exotic leather since 1691