There is a specific moment — pulling on a well-worn cotton shirt on a slow Sunday morning, the kind that glides over your skin with almost no resistance — when fabric stops being something you think about and becomes something you feel. That experience has a name: Pima cotton. A premium variety of extra-long staple cotton, Pima cotton is defined by its exceptional softness, strength, and quietly lustrous finish — qualities that place it among the finest natural fibers in the world. Grown primarily in Peru, the United States Southwest, and Australia, its fibers are significantly longer and finer than standard cotton, producing fabric that feels noticeably smoother against the skin and holds its shape wash after wash. At Eberjey, we've spent nearly three decades studying what makes a fabric worth sleeping in, and Pima cotton's fiber structure answers that question better than almost anything else in the natural fiber world.
What Makes Pima Cotton Different From Regular Cotton?
The single most important distinction between Pima cotton and standard upland cotton is fiber length. Cotton is classified by its staple length — the average length of individual fibers harvested from the cotton boll. Standard upland cotton, which accounts for roughly 90 percent of global cotton production, has a staple length of approximately 1 to 1.125 inches (Cotton Incorporated, 2023). Pima cotton, by contrast, is classified as extra-long staple (ELS) cotton, with fibers typically measuring 1.38 inches or longer (USDA Agricultural Marketing Service, 2022).
Those extra millimeters matter enormously in the finished fabric. Longer fibers mean fewer fiber ends per square inch of fabric, which translates directly into a smoother surface, reduced pilling, and a softer hand feel. When shorter fibers are spun into yarn, their exposed ends create the fuzzy, rough texture that causes pilling and that scratchy feeling against skin. Pima cotton's longer fibers stay tucked within the yarn structure, creating a cleaner, more refined surface (Journal of Natural Fibers, 2021).
Pima cotton also has a finer fiber diameter than standard cotton — measured in microns, it is consistently thinner and more uniform, allowing it to be spun into a finer yarn without sacrificing strength (Textile Exchange, 2022). The result is a fabric that drapes beautifully, feels cool and smooth, and develops a subtle luster similar to that of natural silk.
Where Does Pima Cotton Come From?
Pima cotton has its roots in the Americas, specifically in the ancient cotton varieties cultivated by indigenous peoples of South America. The modern Pima variety was developed in the early twentieth century through selective breeding programs conducted in the United States. Its name derives from the Pima people of Arizona, who assisted U.S. Department of Agriculture researchers in cultivating the crop in the early 1900s (USDA Agricultural Marketing Service, 2022).
Today, the world's most prized Pima cotton comes from Peru. Peruvian Pima cotton is grown primarily along the country's northern coastal valleys, where the combination of consistent sunshine, cool Pacific breezes, and rich alluvial soil creates growing conditions that produce exceptionally long, fine fibers. Peruvian Pima is hand-harvested — a labor-intensive process that avoids the fiber damage that mechanical harvesting can cause — and is widely regarded as the gold standard among ELS cotton varieties.
American-grown Pima cotton is produced primarily in California's San Joaquin Valley, Arizona, New Mexico, and Texas under strict USDA oversight, forming the basis of the Supima certification program (USDA Agricultural Marketing Service, 2022).
Pima Cotton and Supima Cotton: What's the Difference?
This is one of the most common questions shoppers ask, and the answer is reassuringly straightforward. Supima is not a different type of cotton — it is a certification and trademark program that guarantees a product contains 100 percent American-grown Pima cotton (Supima Association of America, 2023). The word "Supima" is a contraction of "Superior Pima."
All Supima cotton is Pima cotton, but not all Pima cotton is Supima. Pima cotton grown in Peru or Australia carries the "Pima" designation but cannot carry the Supima trademark unless it meets the U.S.-grown and program-certified requirements. Both are extra-long staple, both produce premium-quality fabrics, and both are held to high standards — the distinction is primarily one of geographic origin and brand certification.
When shopping for premium cotton goods, either designation signals quality well above standard upland cotton. The Supima trademark provides an added layer of supply chain transparency for those who prioritize domestic American agriculture, while Peruvian Pima carries its own prestige rooted in centuries of cotton-growing tradition (Textile Exchange, 2022).
Why Pima Cotton Belongs in Your Sleepwear Rotation
Pima cotton is exceptionally well-suited for sleepwear, and for reasons that align directly with what the body needs during rest. The skin is at its most sensitive in sleep — body temperature fluctuates, and any fabric roughness or irritation that might be tolerable during the day becomes magnified at night. Pima cotton's smooth, pill-resistant surface means there are no rough fiber ends to create friction against skin over hours of wear (Journal of Natural Fibers, 2021).
Breathability is another key advantage. Pima cotton is a natural cellulosic fiber with strong moisture-wicking properties, allowing it to absorb and release moisture effectively as body temperature changes through the night. This temperature-regulating quality makes it a natural choice for warm sleepers and for anyone living in climates with warm or humid nights. Unlike synthetic fabrics, Pima cotton does not trap heat or moisture against the skin.
Pima cotton's durability also matters for sleepwear specifically — pieces washed several times per week. Standard cotton can fade, pill, and lose its shape relatively quickly under that laundering pressure. Pima cotton's longer, stronger fibers resist pilling and maintain color and shape through significantly more wash cycles, making it a genuinely enduring investment (Cotton Incorporated, 2023). At Eberjey, Pima cotton appears in select styles where that combination of softness, structure, and breathability is precisely what the garment calls for — pieces designed to feel effortless from the first morning you reach for them through years of wear.
How Pima Cotton Compares to TENCEL™ Modal
Pima cotton and TENCEL™ Modal are both premium natural-origin fibers, both prized for softness and longevity — but they come from different sources and offer slightly different wearing experiences.
Pima cotton is a plant-based natural fiber, grown and harvested from the cotton plant. TENCEL™ Modal is a semi-synthetic cellulosic fiber produced by Lenzing AG from sustainably sourced beechwood pulp using a closed-loop manufacturing process that recovers 99 percent or more of the solvents used in production (Lenzing AG, 2023). Both fibers are OEKO-TEX Standard 100 certified when used in premium applications, meaning they have been tested and confirmed free from harmful substances (OEKO-TEX, 2023).
In terms of feel, TENCEL™ Modal has an exceptionally silky, almost weightless drape that many sleepers describe as feeling cooler than cotton against the skin. Pima cotton has a more structured body with a smooth, lustrous surface — it breathes beautifully and has a familiar, comforting weight. Modal tends to have a slightly higher moisture-wicking performance in humid conditions, while Pima cotton offers a classic natural texture that improves with washing. TENCEL™ Modal's closed-loop production process gives it a smaller environmental footprint than conventionally grown cotton, though Pima cotton grown under organic or Supima-certified programs narrows that gap considerably (Textile Exchange, 2022).
Eberjey's hero Gisele PJ Set is made from TENCEL™ Modal. Select Eberjey styles use Pima cotton — the choice between them comes down to personal preference in weight, texture, and wearing climate.
The Sustainability Story Behind Pima Cotton
Cotton's environmental story is layered, and Pima cotton occupies a more considered position within it. Conventional cotton farming is water-intensive and has historically relied on significant pesticide use (Textile Exchange, 2022). Pima and Supima programs have made meaningful strides in addressing these concerns.
American Supima cotton is grown under USDA oversight with increasing adoption of precision irrigation, integrated pest management, and soil health practices that reduce water and chemical inputs (USDA Agricultural Marketing Service, 2022). Peruvian Pima is frequently grown under organic and fair-trade frameworks that prohibit synthetic pesticides and prioritize worker welfare — and its hand-harvesting tradition reduces fossil fuel inputs and fiber damage.
When certified organic, Pima cotton meets GOTS (Global Organic Textile Standard) certification, providing verified supply chain transparency from field to finished garment (Textile Exchange, 2022). The durability of Pima cotton is itself a sustainability argument: a garment that maintains its softness, shape, and color through years of regular washing is one that does not need to be replaced — reducing the total resource cost of a wardrobe over time (Cotton Incorporated, 2023).
How to Care for Pima Cotton So It Lasts
Pima cotton is more forgiving to launder than silk or cashmere, but a few simple practices will extend the life of your pieces considerably and preserve their natural softness.
Wash in cool or warm water rather than hot. High temperatures can cause cotton fibers to contract and weaken over time, contributing to shrinkage and a rougher texture. A delicate or gentle cycle is preferred over a heavy-duty cycle, which creates more mechanical agitation and fiber stress (Cotton Incorporated, 2023). Use a mild, pH-neutral detergent and avoid chlorine bleach, which degrades natural cotton fibers. Fabric softeners are generally unnecessary with Pima cotton — the fiber's softness is inherent to its structure, not dependent on chemical treatments.
For drying, low heat or air drying is ideal. High heat increases the risk of shrinkage and fiber fatigue over repeated cycles. If you notice any wrinkling, Pima cotton responds well to a warm iron or a brief steam — its fibers relax quickly under gentle heat. Store garments folded rather than hung to avoid stress on the fabric structure, particularly for lightweight sleepwear where the fabric's own weight can stretch shoulder seams over time.
Pieces made from Pima cotton — tended to with a little care — become wearable heirlooms. The kind that feel even better after fifty washes than they did on day one.
References & Citations
Cotton Incorporated. (2023). Cotton fiber quality and staple length. Retrieved from https://www.cottoninc.com/fiber/quality/
Journal of Natural Fibers. (2021). Extra-long staple cotton: Fiber characteristics and textile performance. Taylor & Francis. Retrieved from https://www.tandfonline.com/toc/wjnf20/current
Lenzing AG. (2023). TENCEL™ Modal: Botanic origin and production process. Retrieved from https://www.tencel.com/modal
OEKO-TEX. (2023). OEKO-TEX Standard 100: What it means for consumers. Retrieved from https://www.oeko-tex.com/en/our-standards/oeko-tex-standard-100
Supima Association of America. (2023). What is Supima cotton? Retrieved from https://supima.com/what-is-supima-cotton
Textile Exchange. (2022). Preferred fiber and materials market report. Retrieved from https://textileexchange.org/preferred-fiber-and-materials-report/
USDA Agricultural Marketing Service. (2022). Cotton: World markets and trade. United States Department of Agriculture. Retrieved from https://apps.fas.usda.gov/psdonline/circulars/cotton.pdf
