What is a Denim made of?
What is a Denim made of?
A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades.
Everything people like about denim follows from the ring dye. Because indigo only coats the surface of the cotton fibre, abrasion at the knees, thighs and seat exposes the white core underneath, so the garment wears a record of how it has been used — no other common dye behaves this way. Raw or dry denim is unwashed and unsanforised, meaning it will shrink substantially on first wash; sanforised denim has been pre-shrunk mechanically. Denim also carries a serious environmental footprint from indigo synthesis and, historically, from stonewashing and sandblasting, the latter banned by major brands after it caused silicosis in workers.
Component by component
| Part | Material | Why that material |
|---|---|---|
| warp yarn | cotton dyed with indigo | Indigo is insoluble and will not penetrate cotton, so it builds up in layers on the outside of the yarn — a ring dye. |
| weft yarn | undyed cotton | The white weft is why the inside of a pair of jeans is pale and why worn edges go white rather than a lighter blue. |
| weave | 3-over-1 right-hand twill | Three of every four warp threads sit on the face, so the blue side is blue and the reverse is white, and the twill gives diagonal drape. |
| stretch content | 1-3% elastane, in most modern jeans | A very small proportion transforms the fit, but it also breaks down with heat, which is why stretch jeans bag out and tumble drying kills them. |
| hardware | copper or zinc alloy rivets and a metal or plastic zip | Rivets, patented by Jacob Davis and Levi Strauss in 1873, reinforce the pocket corners that tore first in workwear. |
Other clothing and kit objects
- Velcro (hook and loop) Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs.
- Leather Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.
- Gore-Tex A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule.
- Helmet A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact.
- Bulletproof vest Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate.
- Zip (zipper) Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider.
- Synthetic leather A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder.
- Running shoe A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.
- Shoe sole A rubber outsole for grip, a foam midsole for cushioning, and increasingly no clean way to separate them.
- Wetsuit Closed-cell neoprene foam full of nitrogen bubbles, faced with stretch jersey — the gas insulates, not the water.
- Life jacket Closed-cell foam or a CO2-inflated bladder, in a nylon cover — rated in newtons of buoyancy, not in size.
- 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 Denim made of?
- A cotton twill with indigo-dyed warp and undyed weft — the dye sits on the fibre surface, which is why it fades.
- What is the warp yarn of a Denim made of?
- Cotton dyed with indigo. Indigo is insoluble and will not penetrate cotton, so it builds up in layers on the outside of the yarn — a ring dye.
- What is the weft yarn of a Denim made of?
- Undyed cotton. The white weft is why the inside of a pair of jeans is pale and why worn edges go white rather than a lighter blue.
Related pages
- Velcro (hook and loop) Two nylon tapes — one of stiff hooks, one of soft loops — copied directly from burdock burrs.
- Leather Animal hide whose collagen has been chemically stabilised so it cannot rot — usually with chromium salts.
- Gore-Tex A stretched PTFE membrane whose pores are far too small for a raindrop and far too big for a water vapour molecule.
- Helmet A hard shell to spread the blow over a crushable polystyrene foam liner that is destroyed by one impact.
- Bulletproof vest Many layers of woven aramid or polyethylene fibre that catch and deform a bullet; rifle threats need a ceramic plate.
- Zip (zipper) Teeth of metal, moulded acetal or nylon coil on a polyester tape, forced together by a wedge inside the slider.
- Synthetic leather A polyurethane or PVC skin on a textile backing — including the plant-based ones, which still need a plastic binder.
- Running shoe A knitted synthetic upper over a foam midsole and rubber outsole — about a dozen materials, all glued together.
- Pencil Stationery and paper
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Paper Stationery and paper
- Glass Building materials
Sources
- Typical range compiled from manufacturer specifications — At One Place