Fibres · Man-made
Acetate
The artificial silk with an elegant drape: it is born from cellulose but behaves like a melt fibre, lustrous and fluid. Not very elastic and delicate, it gives knitwear a slippery, cool fall that is more decorative than structural.
Translated from Italian. A native knitter has not reviewed this translation yet.
History
Cellulose acetate began as a technical material in the early twentieth century, for lacquers and cinema film, before becoming a textile fibre in the 1920s. It was the great cheap substitute for silk in clothing and linings after the Second World War, when its low-cost lustre made it ubiquitous in evening dresses, scarves and formal wear.
How the yarn is made
The starting point is wood cellulose or cotton linters, which are reacted with acetic acid and acetic anhydride to give a viscous dope. This solution is extruded through spinnerets and solidifies as the solvent evaporates (dry spinning), giving a continuous, smooth and lustrous filament. So there is neither shearing nor staple: the fibre is born already as a yarn.
Why it is prized
Its value is purely aesthetic: it costs little and gives a silky lustre and a soft, heavy drape that few inexpensive fibres can offer. In knitwear it is used for garments that must fall fluidly and shine, where elastic recovery matters less than the visual effect and the depth of colour.
Dyeing
Acetate does not accept the dyes used on other cellulosic fibres and needs specific disperse dyes, the same ones developed for synthetics. Well dyed, it gives deep, brilliant colours on its lustrous surface, but it has historically been prone to fume fading, discoloration caused by atmospheric gases that shifts certain shades, now corrected with stabilised dyes.
Care
It is a delicate, heat-sensitive fibre: wash it by hand or cold with a neutral detergent, iron it at the lowest temperature and on the wrong side, and keep it away from acetone and solvents, which dissolve it. When wet it loses body and strength, so handle it carefully and dry it flat.
End of life
It derives from cellulose and is therefore in principle biodegradable, but the chemical modification slows its breakdown considerably compared with natural fibres. It is not easily recycled into textiles and does not take mechanical regeneration the way wool does: end of life remains the weakest point of its environmental profile.
How to recognise it
| Hand | Smooth, slippery and cool to the touch, with a surface reminiscent of silk but more uniform and free of irregularities. Not very elastic: it gives and stays given. |
|---|---|
| Look | Markedly lustrous and silky, with a continuous, bright sheen. No crimp and no halo: the fibre is smooth and closed, and the yarn looks full and glassy. |
| Behaviour | It drapes fluidly and heavily, stays cool on the body and holds little warmth. It creases in sharp folds and does not recover on its own, because its elastic memory is low. |
| Burn test | Hybrid cellulosic-and-melt signature: it burns and melts at the same time, sizzling, with a sharp smell of hot vinegar (acetic acid) and a residue in a hard, dark bead. |
| Home tests | Burn test: dripping flame, acrid vinegar smell, hard bead · Acetone test: a drop softens or dissolves the fibre, which does not happen with silk or viscose · Elasticity test: pull and release, acetate stays deformed |
| Confused with | Real silk: but silk does not melt in the flame and smells of burning hair, not vinegar · Viscose and other lustrous man-made cellulosics: but viscose does not melt and resists acetone |
| Only in a lab | Telling acetate apart with certainty from the other regenerated cellulose fibres, and quantifying its degree of acetylation, requires laboratory analysis (spectroscopy or standardised solubility according to ISO 1833). |
Physical facts
| Property | Value | Source |
|---|---|---|
| elastic memory | Low | research |
| sag | Medium | research |
| halo | None | research |
| felting risk | None | research |
| fineness (µm) | — | research |
| moisture regain (%) | 6.5 | research |
| typical shrinkage (%) | 1–4 | estimate |
| staple length (mm) | — | research |
measured = a measurement with a reference · iso = a standard · research = a verified source · estimate = plausibility only
Good for
fluid, slippery drape · lustrous and formal garments · linings and decorative details · light evening scarves
Less good for
ribs and cuffs that must spring back · garments under strain or abrasion · hard-wearing everyday knitwear · garments machine-washed often