10/07/2026
Blue and green, side by side. 🟦 🟩
Two hides at exactly the same point in their life.
Freshly tanned, still wet, waiting on the rails for the next process step.
🟦 The blue-grey ones on the left are wet-blue. That colour isn’t dye. It’s the chrome tanning agent reacting with the hide, so the skin comes out of the drum looking bluish.
🟩 The beige-green ones next to them are wet-green, tanned with an extract of olive tree pruning, and that tint comes from the leaves and the wood of the pruned branches.
Neither colour lasts unless wanted. Both can be dyed into almost anything later on, so at this stage the colour only tells you what went into the drum to tan the hide.
Both processes use a similar amount of water, time and energy.
What differs is what happens to the water afterwards.
🟩 A modern tannery or a vegetable tannery with a biological wastewater treatment plant ends up at zero net water consumption. It can take the water from the river, clean it, use it, clean it again and send it back to the river. It only borrows the water for a while.
🟦 Chrome tanning is extremely efficient, and a modern chemical wastewater plant handles it well. But some chrome washes out during the various process steps, and there is always some chromium left in the water. It gets captured and pressed into a filter cake, and that filter cake has to go somewhere. Typically disposed as special waste. Modern chrome tanneries can also clean their wastewater to the point that they can release it back to the river.
What I find most telling is seeing blue and green lying next to each other at all. Keeping both worlds apart without cross-contamination takes a modern setup, care by the tannery workers, and it means the present and the future can work alongside each other in the same building.
🎥
