Fibres and raw materials

Organic cotton is cotton grown without synthetic fertilisers, synthetic pesticides or genetically modified seed. The plant and the fibre are the same as conventional cotton; the difference lies in how it is farmed.

The name "organic" rests on inspection, not on a declaration: the field is certified to organic farming rules, and standards such as GOTS and OCS verify that the fibre is traced from the field to the finished product. The proportion of organic fibre in the product is stated on the label.

In fabric it has the familiar qualities of cotton: it breathes, absorbs moisture and feels soft against the skin. It is typically preferred for T-shirts, sweatshirts, underwear, babywear and socks.

Cotton is obtained from the fibre in the boll that surrounds the seed of the cotton plant. Conventional cotton is cotton grown without organic certification or a special farming programme, and it is the most widely used natural fibre in the world. The fibre is separated from the seed by ginning, combed and spun into yarn.

It is not in the sustainable fibre category; it is on this page to show what the other fibres are compared with. It is the same plant as organic cotton; the difference lies in the field and in the certificates, not in the machine.

In fabric it breathes, absorbs moisture, feels soft against the skin, withstands frequent washing and takes dye well. It is the basic fibre of knitted garments, from T-shirts to underwear and from sweatshirts to socks; for stretch it is usually blended with a small proportion of elastane.

Linen is obtained from the long fibre in the stem of the flax plant. After harvest the stems are left in the field; moisture and microorganisms loosen the fibre from the stem, and the fibre is then separated mechanically. No conversion into a solution is needed to obtain the fibre.

It is called sustainable because of how it is farmed: in the cool, humid climates where it grows, flax is mostly rain-fed, needs little fertiliser, and the parts of the plant other than the fibre are also put to use. This quality comes from the nature of the fibre; there is no separate fibre certificate specific to linen.

In fabric it keeps you cool, takes up and releases moisture quickly, is durable and softens with washing; it creases easily. In knitted garments it is usually preferred in blends with cotton, in summer T-shirts and in homewear.

Hemp fibre is obtained from the fibre in the bark of the stem of the industrial hemp plant. Like linen it is a bast fibre: after harvest the stems are left to rest, the fibre is separated mechanically from the bark and combed for yarn.

It is called sustainable because of how it is farmed: the plant grows quickly, suppresses weeds itself because it is sown densely, and is usually grown with few pesticides and little irrigation. This quality comes from the agricultural characteristics of the fibre; there is no separate fibre certificate specific to hemp.

In fabric it is durable, breathes, absorbs moisture well and softens with washing. Because it can feel stiff on its own, in knitted garments it is mostly blended with cotton and gives the fabric a drier, textured hand feel. It is typically preferred for T-shirts, sweatshirts, socks and casual wear.

Lyocell is a regenerated cellulose fibre produced by dissolving wood pulp in a solvent called NMMO and extruding it as fibre. Its raw material is plant-based, but the fibre itself is produced by a chemical process. TENCEL™ is the brand name Lenzing gives to its lyocell; not every lyocell is TENCEL™.

It is called sustainable because of the process: lyocell is produced in a closed loop and the solvent is used again and again. Lenzing reports that more than 99 per cent of the solvent is recovered (manufacturer data) and states that the wood comes from certified and controlled sources.

In fabric it gives a smooth, soft surface, manages moisture well, stays strong when wet and drapes well. It is typically preferred for T-shirts, underwear, homewear and sportswear, on its own or blended with cotton.

Modal is a regenerated cellulose fibre produced mainly from the wood pulp of the beech tree. It is produced by a chemical process similar to viscose; because the fibre is drawn more tightly, it is finer and stronger when wet.

Its sustainable quality depends on the source of the wood and on the manufacturer recovering the chemicals. Manufacturers that produce wood pulp and fibre at the same site report that they recover most of the process chemicals (manufacturer data). This cannot be said of modal made from wood of uncertified origin.

In fabric it is very soft and keeps this softness through repeated washing; it absorbs moisture well and feels cool against the skin. It is typically preferred for underwear, homewear, loungewear and T-shirts, blended with cotton and elastane.

LENZING™ ECOVERO™ is Lenzing's viscose fibre. The production method is viscose: wood pulp is dissolved chemically and extruded again as fibre. The difference lies in the source of the wood and in how production is carried out.

It is called sustainable because of its certificates: the wood comes from certified and controlled forests, the fibre carries the EU Ecolabel, and the manufacturer reports lower emissions and water impact than standard viscose (manufacturer data). The manufacturer states that, thanks to a special identification system, the fibre can be identified even in the finished fabric.

In fabric it has the qualities of viscose: a soft, fluid, breathable surface and good moisture absorption; it weakens when wet. It is typically preferred for T-shirts, homewear, loungewear and blended knitted fabrics.

Recycled cotton is obtained by mechanically breaking cutting waste and used cotton textiles back down into fibre. The waste is sorted by colour, shredded and turned back into fibre; when sorted by colour, it may not need to be dyed again.

What makes it recycled is its content proportion, which standards such as GRS and RCS verify. The water, land and farming inputs needed to grow new cotton are not used; fibre that already exists is put back to use.

Because the mechanical process shortens the fibre, it is not spun on its own but blended with new cotton or recycled polyester. In fabric it carries the breathability and softness of cotton. It is typically preferred for T-shirts, sweatshirts and socks.

Recycled polyester is mostly produced from used PET bottles. The bottles are sorted, washed, turned into small flakes, melted and extruded again as fibre. Polyester recovered from textile waste also belongs to this group.

What makes it recycled is its content proportion, which standards such as GRS and RCS verify. Because it reuses existing plastic instead of producing new polymer, it reduces the need for fossil raw materials.

In fabric it cannot be told apart from new polyester: it is light, holds its shape, dries quickly and carries sweat to the surface of the fabric. In blends with cotton it adds shape and durability to the fabric. It is typically preferred for sportswear, yogawear and sweatshirts, on its own or blended with cotton.

Recycled polyamide (nylon) is recovered from production waste nylon, used fishing nets and post-consumer waste such as carpets. The waste is either melted and extruded again as fibre, or broken down chemically into its original building blocks and made into polymer again.

What makes it recycled is its content proportion, which GRS and RCS verify. Waste is used in place of the fossil raw material needed for new polyamide; in the chemical method, the remade polymer has the same structure as fossil-based polyamide.

In fabric it is durable, resists abrasion and adds stretch. It is typically preferred for socks, underwear, sportswear and yogawear.

Polyester is a synthetic fibre obtained by melting and extruding as fibre a polymer produced from fossil-based raw materials, terephthalic acid and ethylene glycol. It is the most widely produced fibre in the world.

It is not in the sustainable fibre category; it is used as a conventional fibre for its performance. Its counterpart made from waste, with the same properties, is the recycled polyester on this page; the two cannot be told apart in fabric.

In fabric it is light, holds its shape and colour, dries quickly, does not crease easily and withstands frequent washing. Blended with cotton it gives the fabric durability and shape, while the cotton provides softness against the skin. It is typically preferred on its own for sportswear and yogawear, and blended with cotton for T-shirts and sweatshirts.

Polyamide (nylon) is a synthetic fibre produced from fossil-based raw materials. Polyamide 6, one of its two common types in textiles, is obtained from caprolactam; the polymer is melted and extruded into fine, strong fibres. The other common type is polyamide 6.6.

It is not in the sustainable fibre category; it is used as a conventional fibre for its durability. Its counterpart recovered from waste is the recycled polyamide on this page, and it does the same job in fabric.

In fabric it is highly resistant to abrasion and stretchy; even in small proportions it extends the life of the product. Because of its stretch and strength it is often used in fabrics with elastane. It is typically preferred for areas of socks that wear, such as the heel and toe, and for underwear, sportswear and yogawear.

Acrylic is a synthetic fibre made by spinning a polymer, obtained from fossil-based acrylonitrile, into fibre from a solution. It is spun into yarn as staple fibre.

It is not in the class of sustainable fibres; it is used as a conventional fibre for its handle and colour properties.

In fabric it gives a soft, full, wool-like handle, is light and holds its dyed colour well. In socks and knitted garments it is used on its own or blended with cotton and other fibres.