---
title: "What is a Leather made of?"
description: "Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts. Every component, the material it uses, and the constraint t"
url: https://atoneplace.net/made-of/leather/
site: "At One Place"
---

# What is a Leather made of?

**What is a Leather made of?: Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.**

Tanning exists to stop the hide doing what skin naturally does, which is rot. Untanned hide dries to rawhide, hard and brittle, and softens and putrefies when wet; tanning agents crosslink the collagen so it stays flexible and resists water and microbes permanently. The grading vocabulary is worth knowing because it is designed to confuse: full grain keeps the outermost, strongest layer with its natural markings; top grain has been sanded to remove flaws; "genuine leather" is a lower split; and bonded leather is leather dust in polyurethane, which delaminates within a few years. Chrome tanning is efficient but the effluent, particularly where trivalent chromium can oxidise, is a serious pollution problem in poorly regulated tanneries.

## Component by component

*Every material is a choice, and the third column is the constraint that drove it.*

| Part | Material | Why that material |
| --- | --- | --- |
| hide | cattle, sheep, goat or pig skin, mostly a by-product of meat production | The dermis is a dense three-dimensional collagen network, which is what gives leather its unusual combination of strength and drape. |
| chrome tanning | basic chromium(III) sulfate | It crosslinks the collagen in a day, gives soft, supple, water-resistant leather, and accounts for the large majority of production. |
| vegetable tanning | tannins from oak, chestnut, mimosa or quebracho bark | It takes weeks in pits but gives firm leather that can be tooled and moulded, and that develops a patina — belts, saddlery, shoe soles. |
| finish | dyes, pigments, and a polyurethane or acrylic top coat | A heavier pigment coat hides flaws in poor hides, which is exactly why cheap "corrected grain" leather looks plasticky. |
| grades | full grain, top grain, genuine leather, bonded leather | "Genuine leather" is a low grade, and bonded leather is shredded scrap glued onto a backing — the naming is deliberately misleading. |

## Other clothing and kit objects

- [Velcro (hook and loop)](https://atoneplace.net/made-of/velcro/) — Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs.
- [Gore-Tex](https://atoneplace.net/made-of/gore-tex/) — A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule.
- [Denim](https://atoneplace.net/made-of/denim/) — A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades.
- [Helmet](https://atoneplace.net/made-of/helmet/) — A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact.
- [Bulletproof vest](https://atoneplace.net/made-of/body-armor/) — Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate.
- [Zip (zipper)](https://atoneplace.net/made-of/zipper/) — Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider.
- [Synthetic leather](https://atoneplace.net/made-of/synthetic-leather/) — A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder.
- [Running shoe](https://atoneplace.net/made-of/running-shoe/) — A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.
- [Shoe sole](https://atoneplace.net/made-of/shoe-sole/) — A rubber outsole for grip, a foam midsole for cushioning, and increasingly no clean way to separate them.
- [Wetsuit](https://atoneplace.net/made-of/wetsuit/) — Closed-cell neoprene foam full of nitrogen bubbles, faced with stretch jersey — the gas insulates, not the water.
- [Life jacket](https://atoneplace.net/made-of/life-jacket/) — Closed-cell foam or a CO2-inflated bladder, in a nylon cover — rated in newtons of buoyancy, not in size.
- [Button](https://atoneplace.net/made-of/button/) — Usually cast polyester resin; the good ones are shell, nut or horn, and you can tell by touch and temperature.

## Common questions

### What is a Leather made of?

Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.

### What is the hide of a Leather made of?

Cattle, sheep, goat or pig skin, mostly a by-product of meat production. The dermis is a dense three-dimensional collagen network, which is what gives leather its unusual combination of strength and drape.

### What is the chrome tanning of a Leather made of?

Basic chromium(III) sulfate. It crosslinks the collagen in a day, gives soft, supple, water-resistant leather, and accounts for the large majority of production.

## Related pages

- [Velcro (hook and loop)](https://atoneplace.net/made-of/velcro/)
- [Gore-Tex](https://atoneplace.net/made-of/gore-tex/)
- [Denim](https://atoneplace.net/made-of/denim/)
- [Helmet](https://atoneplace.net/made-of/helmet/)
- [Bulletproof vest](https://atoneplace.net/made-of/body-armor/)
- [Zip (zipper)](https://atoneplace.net/made-of/zipper/)
- [Synthetic leather](https://atoneplace.net/made-of/synthetic-leather/)
- [Running shoe](https://atoneplace.net/made-of/running-shoe/)
- [Pencil](https://atoneplace.net/made-of/pencil/)
- [Tennis ball](https://atoneplace.net/made-of/tennis-ball/)
- [Banknote](https://atoneplace.net/made-of/banknote/)
- [Golf ball](https://atoneplace.net/made-of/golf-ball/)
- [Paper](https://atoneplace.net/made-of/paper/)
- [Glass](https://atoneplace.net/made-of/glass/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)