Cupro

Overview

Production: about 17,000 tonnes per year (capacity) (Bemberg cupro production capacity; Asahi Kasei states it is the only cupro manufacturer, recent). Main producers: Japan. [4]

Regenerated cellulose made by a cuprammonium process, often using cotton linters as feedstock.

Feel and behavior

Fine, smooth and fluid.

Where you find it

Linings, dresses and delicate woven fabrics.

Source and geography

Cupro is regenerated cellulose made by dissolving purified cellulose in a copper and ammonia solution. The usual feedstock is cotton linter, the short fuzz left on cottonseed after ginning, which is too short to spin as cotton but is nearly pure cellulose. Commercial production has contracted to a single major source: Asahi Kasei states that it is the only manufacturer of cupro, sold as Bemberg, and that it has produced the fiber at Nobeoka in Miyazaki Prefecture, Japan, since 1931.

Worth knowing

• Because Asahi Kasei states it is the sole cupro manufacturer, cupro is one of very few generic fibers whose global supply traces to a single company.
• A Circle Economy case study puts Bemberg production capacity at about 17,000 tonnes a year, small next to global viscose output.

Types, grades and fabrics

Types and grades

Cupro reaches the market mainly as continuous filament yarn in very fine deniers, which gives thin, smooth linings, and also in staple and nonwoven forms. Asahi Kasei sells it under the Bemberg name and reports a production capacity of about 17,000 tonnes a year. Within that range, yarns differ by fineness, luster (bright or dull), twist, and whether they are textured for stretch or bulk. Fabric producers then finish cupro with sanding or peach finishing for a suede-like surface, or leave it smooth for linings. Because Asahi Kasei states it is the only cupro manufacturer, a garment labeled cupro can generally be traced back to that producer, though fabric and garment makers are many.

Fabrics and products

The classic use is lining: plain-weave and twill cupro linings in tailored jackets, coats and suits, where the fiber's smoothness and moisture uptake make the lining feel less clammy than polyester. Cupro is also woven into fluid dress fabrics, blouses and trousers, often with a sanded or washed finish that gives a soft, matte, suede-like touch. Knitted cupro jersey is used for underwear and loungewear, and cupro is blended with cotton, wool, linen or elastane. Staple and nonwoven forms serve smaller specialty markets.

Buying and care

How to judge quality

A good cupro lining is thin, dense and smooth, with no fuzz, and it should slide easily against a sleeve. Hold it to the light to check for even weave and consistent color. Sanded cupro should have a uniform, fine peach surface without bald or shiny patches. Labels in the EU say cupro; in the US, check that the generic name follows FTC rules rather than just 'Bemberg'. Terms such as 'vegan silk' are marketing phrases, so confirm the fiber content. Cupro costs more than polyester lining, so a cheap 'cupro-look' lining may be viscose or polyester; ask the seller for the content.

Care in detail

Follow the label, which often specifies dry cleaning for tailored linings. For washable cupro garments, hand wash or use a delicate cycle in cool water with a mild detergent, and avoid wringing, which can distort wet fibers. Roll in a towel to remove excess water, then hang or dry flat away from direct heat; tumble drying can shrink it. Iron on a low to medium setting, on the reverse and while slightly damp, using a pressing cloth to avoid shine. Sanded cupro can show water marks and creases, so treat stains gently with water and blotting rather than rubbing.

Care at a glance

Follow the complete product’s care label. Blends, dyes, finishes and construction can change suitable washing, drying and storage.

Environmental and social footprint

Cupro's feedstock is cotton linter, a short fiber left on cottonseed that would otherwise go to lower-value uses, so it adds no extra farmland. The main environmental question is the cuprammonium process: copper and ammonia must be captured, or they end up in wastewater. Asahi Kasei states that it operates a closed-loop system that recovers and reuses copper and ammonia, and a Circle Economy case study summarizing the producer reports recovery of more than 99 percent of water and solvents; these are producer claims without independent audit data in the public record reviewed here. As a regenerated cellulose, cupro biodegrades under conditions where cotton and viscose do, but dyes and finishes can change this. Comparative, peer-reviewed life cycle assessments for cupro are scarce.

Tradeoffs

Origin, processing inputs, labor, product construction and useful lifetime all need specific evidence. The name alone does not establish responsible production.

A useful question to ask: What exact material, product form and documented producer stand behind this name?

Science

Manufactured cellulose family

Regenerated cellulose or a cellulose derivative, depending on the fiber.

Structure and chemistry

Chemically cupro is cellulose, a linear polymer of beta-1,4-linked glucose, regenerated into the cellulose II crystal form shared with viscose and lyocell. Unlike acetate, it carries no substituent groups once regeneration is complete, so it has the full complement of hydroxyl groups and is hydrophilic. Filaments are typically very fine, and their cross-section is nearly round and smooth, without the serrated outline and surface striations typical of standard viscose. This smooth, fine, round filament is the physical basis for the soft hand and slippery surface prized in linings.

From source to yarn

Cellulose is dissolved in Schweizer's reagent, an aqueous ammonia solution of tetraamminecopper(II) hydroxide, [Cu(NH3)4](OH)2, formed from copper salts and ammonia. The deep blue solution is filtered and extruded through relatively wide spinneret holes into a stream of water flowing through a funnel. In this stretch spinning step, developed by Edmund Thiele, the flowing water draws the still-plastic filaments down to fine deniers as the cellulose begins to regenerate. The filaments are then treated to complete regeneration and remove residual copper and ammonia, washed and wound. Recovering copper and ammonia is central to the environmental profile, so buyers should request producer data on recovery.

Performance in use

As regenerated cellulose, cupro absorbs moisture readily and handles static well, which is why it is favored for linings that sit against the body. Its hydroxyl-rich structure accepts the dye classes used for cotton and viscose, including reactive and direct dyes. Like other regenerated celluloses, it is weaker wet than dry and can shrink or distort if washed or wrung roughly, so care labels often call for gentle handling. It is not thermoplastic and chars rather than melts under heat. Its smooth filament surface resists fuzzing but can show abrasion at friction points.

How it is identified

Burn tests are indicative only: like other cellulosics, cupro burns quickly with an afterglow, smells like burning paper and leaves soft grey ash without a hard bead. Microscopy is more useful, showing fine, round, smooth filaments that differ from the serrated cross-section of standard viscose. Distinguishing cupro from modal or lyocell can require specialist microscopy or producer documentation. Cupro is sometimes marketed as 'vegan silk', which is a marketing phrase, not a fiber name.

History

Timeline

1. 1857Matthias Eduard Schweizer found that cotton dissolves in a solution of copper salts in ammonia. [1]
2. 1890Louis-Henri Despeissis patented spinning fibers from cuprammonium cellulose solutions. [2]
3. 1908J. P. Bemberg began selling fine stretch-spun cuprammonium artificial silk under the Bemberg name. [3]
4. 1931Japanese cupro production began at Nobeoka, after J. P. Bemberg licensed its process to Shitagau Noguchi in 1928. [3]

Cupro belongs to the early family of artificial-silk processes. Its later use in fine linings reflects the ability to produce smooth cellulose filaments.

The deeper record

In 1857 the Swiss chemist Matthias Eduard Schweizer found that cotton dissolves in a solution of copper salts in ammonia and can be regenerated from it. In 1890 the French chemist Louis-Henri Despeissis patented spinning fibers from such solutions, but he died in 1892 and the patent lapsed. By 1891 Max Fremery and Johann Urban were making lamp filaments at Oberbruch near Aachen by this route, filing under the name of Hermann Pauly to avoid alerting competitors. Edmund Thiele's stretch spinning for J. P. Bemberg produced fine artificial silk sold as Bemberg from 1908. Bemberg licensed the process to Shitagau Noguchi in 1928, and Japanese production began in 1931.

Labeling and law

Regulation (EU) No 1007/2011, Annex I, lists cupro as a fibre name for regenerated cellulose fibre obtained by the cuprammonium process. In the United States, the generic name must come from the FTC list in 16 CFR 303.7; because cupro is a regenerated cellulose, sellers should check that list and FTC guidance for the correct US expression rather than assume the EU name carries over. Bemberg is Asahi Kasei's trademark and does not replace the generic fiber name.

This describes what rules and standards cover. It is not legal advice; jurisdiction, product form and current rule text control.

Frequently asked

Is cupro the same as Bemberg?

Bemberg is Asahi Kasei's trademark for cupro, a regenerated cellulose fiber made through the cuprammonium process. Asahi Kasei states it is the only cupro manufacturer, so most cupro on the market is Bemberg, but labels should give the generic fiber name.

Is cupro better than polyester for linings?

Cupro absorbs moisture and resists static, so it feels cooler and less clingy than polyester lining. Polyester is stronger when wet, cheaper and easier to wash. Cupro is often chosen for tailored wool jackets, while polyester suits hard-wearing or frequently washed garments.

Can you wash cupro?

Some cupro garments are washable, but many tailored items with cupro linings are dry clean only. When washing is allowed, use cool water, a gentle cycle or hand washing and no wringing, because cupro is weaker when wet and can shrink.

Is cupro sustainable?

It uses cotton linter, a byproduct, and Asahi Kasei states it recovers most of its copper and ammonia. However, independent life cycle data are limited, so claims should be treated as producer statements. Its durability and dye and finish choices also matter.

Sources

• Museum of Fine Arts, Boston: Manufactured-fiber reference
• Britannica: Cuprammonium rayon
• Asahi Kasei: Bemberg history (producer source)
• Museum of Design in Plastics: Cuprammonium rayon
• EUR-Lex: Regulation (EU) No 1007/2011 on textile fibre names
• Asahi Kasei: Bemberg sustainability (producer source)
• Circle Economy Knowledge Hub: Asahi Kasei, Bemberg a regenerated cupro fibre made from cotton by-product
• Asahi Kasei: Bemberg cupro fiber official website

Cite this page

Chaos. (2026). Cupro. In Fibers of Earth: An independent textile atlas. https://www.hendrickresearch.com/fibers/materials/cupro/