The global textile industry's sustainability ambitions are facing commercial realities of fiber sourcing. Despite growing pressure to reduce waste and emissions, polyester continues to dominate production, supported by scale, cost advantages and established manufacturing infrastructure.

The white paper The Fiber Wars: Cotton and Synthetics in the Next Decade, published by Gherzi Americas and co-authored by Robert Antoshak and Radhika Shrinivas, examines the forces shaping competition between natural and synthetic fibers. Its central argument is that sourcing decisions depend not only on sustainability commitments but also on raw material prices, manufacturing economics, product performance and downstream margins.

According to Textile Exchange data cited in the report, global fiber production reached 132 million tonnes in 2024. Polyester accounted for 78 million tonnes, or 59 per cent, while cotton was approximately 19 per cent. Cotton volumes have remained broadly stagnant since the 2007/08 crop cycle, leaving synthetic fibers to capture most incremental growth.

Price drives the shift

Polyester's increase reflects a cost advantage. Produced continuously from petrochemical feedstocks, polyester staple fiber (PSF) and filament avoid the seasonal and climatic risks associated with cotton cultivation. Between 2007 and 2026, cotton traded at an average price approximately 1.7 times that of polyester staple fiber, reveals the report. This sustained 70 per cent premium influenced investment in spinning equipment, fabric development and sourcing networks, embedding synthetic fibers into established supply chains.

For mills and manufacturers, switching fibers involves more than comparing spot prices. Machinery, yarn specifications and fabric programmes create substantial switching costs. Cotton must therefore compete on durability, comfort and total commercial value, rather than price alone.

Table: Global fiber production

Sources: Textile Exchange, USDA, US EPA and Cotton Incorporated, as cited in the supplied report.

Fast fashion faces a reset

Polyester's growth has been closely associated with high-volume, low-cost fashion. The Ellen MacArthur Foundation documented how clothing production doubled between 2000 and 2014 while garment wear-rates declined by 36 per cent. The report estimates polyester accounts for 64 per cent of Shein's fabric mix, compared to 27 per cent at Inditex and 21 per cent at H&M. These models benefited from inexpensive synthetic materials, rapid product turnover and direct-to-consumer distribution.

However, the US removal of the $800 de minimis customs exemption, implemented for China and Hong Kong shipments in May 2025 and extended to other origins in August 2025, challenged the economics of low-value cross-border shipments. Subsequent reporting on Shein's first-quarter 2026 performance cited an unaudited $99 million loss, against a $395 million profit a year earlier, along with a 14 per cent decline in US sales. While tariffs are not the only factor affecting performance, the developments underline the pressure on ultra-fast fashion's operating model.

As products move into established value-retail channels, suppliers may face more rigorous quality assurance and wear-testing requirements, increasing the importance of yarn consistency, fabric stability and garment longevity.

Resale rewards durability

The second-hand market is adding a financial dimension to product quality. ThredUp and GlobalData reported 58 per cent of US consumers participated in second-hand shopping in 2024, with the resale apparel market projected to reach $74 billion by 2029. Cheap garments that pill, lose shape or deteriorate after repeated washing struggle to retain resale value. This creates an opportunity for cotton-rich constructions in everyday categories where comfort, moisture absorption and repeated laundering matter.

Polyester retains advantages in applications requiring stretch recovery, lightweight construction and rapid drying. The opportunity lies in matching fiber selection to end-use requirements rather than treating cotton and synthetics as interchangeable commodities.

Recycling hits feedstock limits

Recycled polyester has become the industry's principal sustainability proof point, but Gherzi's analysis highlights constraints in feedstock availability and textile recycling infrastructure. Recycled polyester production reached almost 9.3 million tonnes in 2024, equivalent to around 12 per cent of polyester output. Roughly 98 per cent of recycled polyester feedstock came from mechanically recycled PET bottles, while textile-to-textile recycling remained close to 1 per cent of total global fiber supply.

European Union requirements for recycled plastic in PET beverage bottles have intensified competition for recycled feedstock. Packaging manufacturers with regulatory obligations compete with textile producers for the same material, potentially raising costs for mills.

Recovering fiber from discarded garments is more complex because of blended compositions, elastane, dyes, coatings, buttons and zippers. Recyclers also face competition from virgin polyester producers that can lower prices when petrochemical costs fall, undermining the economics of capital-intensive recycling plants. Consequently, recycled-content claims alone cannot deliver circularity at scale. Better sorting, traceability and commercially viable textile-to-textile technologies remain essential.

Regulation raises waste costs

The EU's revised waste framework requires member states to implement textile producer-responsibility schemes by April 2028. The bloc's ban on destroying unsold apparel also took effect for relevant companies in July 2026, while rules targeting misleading environmental claims increase scrutiny of sustainability marketing. For mills and brands, fiber selection is becoming a product-design and compliance decision. Complex blends may deliver useful performance but complicate recycling and increase end-of-life management costs.

Basics become the battleground

Gherzi identifies denim, T-shirts, underwear, sleepwear, towels and hosiery as important arenas for fiber competition. In these high-volume categories, comfort, pilling, odor retention and durability can influence repeat purchases.

Socks reveal the economics. Cotton-rich constructions offer comfort and moisture absorption, while nylon or polyester reinforcement improves heel-and-toe abrasion resistance. Elastane provides stretch and recovery. The optimum solution is a performance-led blend rather than necessarily an all-cotton product.

Consider a hypothetical programme of 100,000 garments. Replacing a premium construction with a cheaper alternative saves 20 cents per unit, generating $20,000. But if 5,000 garments expected to sell for $20 require markdowns to $14, the $30,000 revenue reduction exceeds the initial savings.

The report also estimates that a 40-cent increase in cotton cost per kilogram adds just 12.5 cents in fabric cost to a garment using a quarter-kilogram of fabric. Small procurement savings can therefore be outweighed by weaker sell-through and higher markdowns.

Sourcing beyond price

Polyester is unlikely to surrender its scale advantage, particularly in technical and performance applications. Cotton, however, has opportunities where comfort, longevity and resale value matter. For spinners, fabric manufacturers and fiber suppliers, the strategic priority is to assess material costs alongside manufacturing efficiency, product life, recyclability and downstream margins. Fiber choices that look cheaper at the purchase-order stage may prove more expensive across the product lifecycle. Gherzi's important message is that sustainability must work commercially at the level of factory economics and balance sheets, not just corporate targets.