@spot_material
hello@spotmaterial.com
Cotton
1.2-4 usd/kg
Cotton is a very important fibre that makes up 80% of all natural fibre sales and accounts for around 25% of total fibre consumption, second only to polyester.
It is a soft and breathable cellulose fibre obtained from the boll (seedpod) of the cotton plant (Gossypium genus). The fibre is hollow and highly absorbent. It can swell to take on water, many times its own weight. In use since prehistoric times, it continues to be popular even though many synthetic alternatives have emerged in recent years.
It is supple with very good drape – qualities that are the result of its role on the plant. Unlike leaf fibres and those from the stems of plants (bast fibre), cotton does not play any structural role. It is light and airy, and almost pure cellulose. This means it takes dye very well, and so is available in a range of high quality and consistent colours.
Cotton is naturally off-white, or a muted shade of red, green or brown. These naturally coloured varieties are hard to come by (check out Foxfibre by Sally Fox in US). Most cotton is off-white and bleached to a bright white before dyeing with colour. Unfortunately, this is part of the problem with cotton. While it is renewable, and potentially a positive circular ingredient in textiles, the techniques used to mass produce it are harmful and use significant quantities of chemicals. Globally, cotton accounts for around 5% of all pesticide sales and 10% of insecticide sales. While not all toxic, many of these chemicals are known to be harmful people and the planet. Once harvested, the cotton fibre is bleached, scoured, mercerised and dyed. Altogether, it results in one of the least sustainable natural fibres.
Sustainability concerns
Raw material generates polluting by-products
Most cotton goes into apparel – tops, trousers, undergarments, t-shirts, dresses, skirts, nightwear, scarves, shawls, linings – and many fabrics have evolved around its specific qualities. For example, denim (workwear), terry (towels, robes and dressing gowns), velveteen, corduroy and seersucker. Densely woven cotton, such as Ventile, is naturally weatherproof. Used in outerwear, as well as tents and other outdoor gear, the fibres swell when wet, and become stronger, which closes up the gaps in the weave structure and so prevents water from getting through. Other applications include packaging, crafts, toys, interior and household fabrics, tablecloths, drapes and bedding.
Cotton fibre is graded according to length, uniformity, colour, fineness and strength. There are three main groups:
– Upland cotton (Gossypium hirsutum) yields a medium to long fibre and makes up the majority of global production. There are several varieties and hybrids. The most popular produces a fibre of around 22-25 mm.
– Extra long staple (ELS) (Gossypium barbadense), which yields a fibre length of 25 mm or more, produces the highest quality fabrics. There are several varieties, such as American pima (Supima) and Egyptian giza.
– Asiatic cotton varieties (such as Gossypium herbaceum and Gossypium arboreum), cultivated in India and central and eastern Asia, yield a short to medium staple ranging in length from 12-25 mm.
Cotton fabrics are pre-shrunk in most cases. This process, known under the trade name Sanforized, is carried out to ensure the fabric does not shrink when washed or further processed. It is essential to ensure high quality items that maintain their shape. Cotton that has not been treated may shrink 10% or more.
Coatings are applied to enhance the longevity and durability of cotton fabrics. For example, wax is repairable, and polyurethane resin (PUR) reduces the amount a fabric needs to be washed, which saves water and energy over its lifetime.
