The Wonder Looper Sweatpants in Iron Mordant Foxfibre® Coyote 80 are made from one of the heaviest French terry fabrics in production today, weighing an exceptional 825 GSM (24.3oz/yd²). The deep, earthy brown tone is not created through conventional dyeing. Instead, it comes from Foxfibre®, a rare naturally pigmented cotton grown organically on a single-origin farm in New Mexico, and is further intensified through an iron mordant treatment. This traditional process causes the cotton’s natural tannins to react, deepening and maturing the color, which continues to slowly darken with wear and exposure to sunlight—developing a unique patina over time.

The Coyote 80 fabric blends 80% Foxfibre® with 20% organic Extra Long Staple cotton, giving the sweatpants a dense yet soft hand feel with excellent durability. Knit in Wakayama, Japan, on low-gauge (10G) circular knitting machines, the fabric features a richly textured exterior and large, comfortable interior loops, offering both structure and comfort.

These sweatpants feature a modern straight-leg fit, designed to be clean and wearable rather than slouchy. They include an elastic drawstring waistband, front slash pockets, a rear patch pocket, and ribbed side panels that provide better movement and visual structure. Finished with flat seam construction, they are built to last and made with the same level of craftsmanship found across Wonder Looper’s most sought-after garments.

Fit Notes: Despite being a Japanese brand, we find the sizing of Wonder Looper garments to be more Western than Japanese. If you usually wear a size M in American pants, you'll find a suitable fit with this piece in size M. However, as always, we recommend consulting our size chart for the perfect fit.