VEGETABLE TANNING
Pelt to Leather Through Mimosa Tannage
Karim Tanneries brings decades of tannery experience to its mimosa-based vegetable tanning in Gujranwala, Pakistan. In large wooden drums, prepared goat and sheep pelts become leather.
THE TANNING PRINCIPLE
Tannins Penetrate the Pelt to Create Leather
For decades, Karim Tanneries has prepared its tanning liquors from solid and powdered mimosa extract. These processed extracts come from wattle bark; raw bark never goes directly into the drums. Tanbark, Karim Tanneries' own design brand, takes its name from tanning (TAN) and the tannin-rich bark traditionally used in vegetable tanning (BARK).
Their tannins penetrate the pelt and fix within its collagen structure, stabilising it as leather. This principle underpins the three-stage tannage — pretanning, principal tanning and retanning — which Karim Tanneries also uses for the hair-on leather it produces for Tanbark.
A Three-Stage Vegetable Tannage
THE TANNAGE
Karim Tanneries puts this principle into practice through three connected stages in large wooden drums: pretanning, principal tanning and retanning. Each stage has a distinct purpose and builds on the work of the last.
01 — Pretanning
At Karim Tanneries, pretanning begins in the pickle float — the liquid used during pickling. Powdered mimosa extract is introduced together with tanning liquor prepared from solid mimosa extract, beginning the pelt's contact with vegetable tannins.
The purpose is controlled initial tannin penetration ahead of principal tanning. This connects the prepared pelt from the beamhouse sequence to the vegetable tannage that follows.
02 — Principal Tanning
Principal tanning follows pretanning and takes place in large wooden drums. Karim Tanneries uses tanning liquor prepared chiefly from solid mimosa extract for this stage.
This is the stage in which the prepared pelt becomes leather. The material then proceeds to retanning, where further vegetable extracts develop its body and character.
03 — Retanning
After principal tanning, Karim Tanneries retans the leather with quebracho, chestnut and oak extracts. These vegetable extracts contribute to the fuller body and structured character of the leather.
Each extract brings a different natural tanning chemistry and balance of firmness, tone and fullness to the leather. Karim Tanneries combines all three in one retanning stage to draw on their complementary strengths.
EXPERIENCED JUDGMENT
Managing Natural Variation Between Lots
Goat and sheep respond differently to tannage, and even within a single species, every lot brings its own variation in texture and character.
Karim Tanneries manages this variation through observation, touch and practical knowledge built up over decades, assessing how the material is responding at every stage. That judgment works alongside the tannery's own machinery, guiding processing decisions.
WHAT FOLLOWS
Toward Natural Crust Leather
After retanning, the leather continues through neutralisation and fatliquoring, followed by natural crust preparation, including hand oiling, natural hanging drying, slickering and trimming. The resulting leather remains undyed and without surface finishing.
Production & Quality follows these operations through inspection, selection, grading and storage. Once a buyer's order is confirmed, the leather is individually measured and packed for supply.
EXPLORE KARIM TANNERIES
The Knowledge Behind the Leather
Leather
Assess grain, body and handle in vegetable-tanned goat and sheep leather supplied in natural crust state, and explore grading and samples.
Production & Quality
From raw-material selection to natural crust preparation, inspection, grading and storage, followed by individual measurement and packing after order confirmation.
Surface Development & Applications
Material handling guidance, plus buyer-led dyeing, finishing and trials to assess natural crust leather for its intended use.
Tannery to Design
Tanbark, Karim Tanneries' design brand for interiors: hair-on rugs, engraved calligraphy, artwork and custom work.
Heritage
Five generations of family history, tannery operations since 1960 and the people leading Karim Tanneries today.
Resources
Materials and processes, buyer-led development and Tanbark design, company and family history, buying and sourcing, plus photographs inside the tannery.
