Solidaridad and Good On You’s 2025 Cotton Rankings, paired with Textile Exchange’s latest fiber market data, expose how fashion’s sustainability claims measure up against the reality of global material use.
The newly released Cotton Rankings Report from Solidaridad, compiled with proprietary brand data from Good On You, offers the clearest snapshot yet of how brands use one of fashion’s most iconic fibers. Cotton, long positioned as natural and renewable, is increasingly marketed as “sustainable,” but the report reveals how much of that language conceals as much as it claims. When paired with the latest material market analysis from Textile Exchange, the data show a concerning trend: synthetics are still surging, polyester dominates, and cotton’s certified share, though rising, remains a fraction of the industry’s overall material footprint.
The Cotton Rankings Report examined 100 brands, ranging from Adidas and H&M to Walmart and Ikea, measuring not only the percentage of certified cotton but also the total volume used and the balance between cotton and synthetics. The findings highlight a persistent gap between consumer-facing narratives and the reality of fiber sourcing.
Adidas proclaims, “Since the end of 2018, 100 percent of the cotton we use has come from more sustainable sources.” Yet cotton represents just 12 percent of its overall material mix, while synthetics account for 54 percent. Puma makes a similar claim, stating that 99 percent of its cotton is certified, but cotton forms only 10 percent of its fiber portfolio, compared with 50 percent synthetics.
The transparency gap in cotton claims
The most pressing issue raised by the rankings is how brands communicate certifications. Solidaridad and Good On You recognize a spectrum of schemes, from Better Cotton and Cotton made in Africa to organic, Fairtrade, the US Cotton Trust Protocol, and recycled cotton. But only 35 of the 100 brands offered a clear breakdown of which certifications they use. The rest lean on vague descriptors like “preferred” or “sustainable” cotton.
Kate Hobson-Lloyd, sustainability manager at Good On You, said, “As an analyst working on this project, there were too many instances of brands saying, ‘we source x amount of preferred cotton’ and the definition of preferred being really vague.” Even when definitions are provided, she added, they are rarely tied to third-party certification: “How is anyone supposed to pull all this apart?”
A handful of companies — Adidas, H&M, Jack Wolfskin, and C&A — publish detailed percentages of their cotton tied to certifications, setting a higher bar. Hobson-Lloyd acknowledged the challenge but stressed the importance of disclosure. “I don’t underestimate how much work must go into all that traceability, and even better, to go ahead and publish it for consumers to see, but if one brand can do it, I don’t see why other brands can’t.”
Transparency extends beyond certifications to volumes, another sticking point for the industry. Only 29 of the 100 brands disclose how many tonnes of cotton they use annually. Tamar Hoek, senior director and head of Solidaridad’s global fashion portfolio, suggested that reluctance is often deliberate. Some brands may wish to obscure their buying power, while others may prefer not to highlight how little they actually use.
The differences, however, are striking when disclosure is made. Inditex, parent of Zara, reports using nearly 300,000 tonnes of cotton, with 69 percent certified. That still leaves more than 92,000 tonnes uncertified, a figure larger than many competitors’ entire consumption. Zalando, by contrast, uses just 2,788 tonnes, but nearly all of it is certified. One brand demonstrates scale with room to shift agriculture at its root, while the other shows the limits of certification when overall usage is marginal.
Global fiber trends point to polyester’s dominance
Textile Exchange’s latest market report situates these findings in a wider context. Global fiber production climbed to 132 million tonnes in 2024, a 6.5 percent increase from the previous year. Synthetics continue to dominate, making up 69 percent of the total, with polyester alone at 59 percent. Recycled polyester grew modestly from 8.9 to 9.3 million tonnes, but its overall share fell as virgin production outpaced it. Cotton’s global share dropped to 19 percent, with 24.1 million tonnes of virgin cotton produced. Encouragingly, certified cotton rose to 34 percent of the total, compared with 28 percent the year before, though recycled cotton remains steady at just one percent.
Other fibers hold comparatively minor shares. Cellulosics such as viscose and lyocell make up about six percent of global production, while flax and hemp together account for less than half a percent. Animal fibers remain marginal as well, with wool at 0.9 percent of the global total, though the proportion of recycled wool has increased from six to seven percent. These figures highlight a growing dependency on synthetics, which remain closely tied to fossil fuel extraction.
Beth Jensen, chief impact officer at Textile Exchange, explained that “key drivers [for the growth of synthetics] could include the demand for performance characteristics, as well as the low cost of virgin fossil-based synthetics, particularly polyester, and the scalability that this can offer global brands.”
That dependency explains why synthetics feature prominently in a cotton-focused report. As Hoek put it, “If a brand uses 100 percent certified cotton and it’s just five percent of its material mix and the rest is virgin synthetics, how sustainable is it as a company?” Cotton may resonate with consumers as natural and renewable, but in many cases, it represents only a sliver of what brands actually use.
Hoek acknowledges cotton is not without its challenges, from pesticide use to regional water concerns. But she points out its potential to support regenerative farming, biodiversity, and rural livelihoods. Synthetics, by contrast, remain 88 percent virgin according to Textile Exchange, with limited pathways to sustainability at scale.
The reports, taken together, underline the need for disclosure that reflects volumes, certifications, and material mixes rather than marketing slogans. As Hoek concluded, “The fashion industry has a choice: double down on fossil-fuel fibers or unlock cotton’s potential as a force for good.”
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