Why Even Our Bio-Based Fabrics Are 5-7% Synthetic

Look closely at almost any 444 garment built to move with the body and you'll find a small synthetic percentage sitting inside an otherwise bio-based fabric. Our castor oil and corn compression pieces run 93 percent biobased PLA to 7 percent elastane. Our blend carries a similar small percentage of the same material. We could hide this. We're choosing not to.

Elastane, also called spandex, is a polyurethane-based polymer, built from diisocyanates and polyols reacted together in a process called polyaddition. It was invented in 1958 by a DuPont chemist named Joseph Shivers, and it remains, more than sixty years later, close to the only fiber capable of stretching four to seven times its resting length and returning cleanly to shape, wash after wash, without degrading.

Nothing bio-based does this at commercial scale yet. Natural fibers like wool and cotton have some give, but nowhere near elastane's range, and none of them recover their exact original shape the way elastane does after hundreds of stretch cycles. A handful of early-stage bio-based and recycled-content stretch fibers exist in development and pilot production, and we're watching that space closely, but none currently perform at the level or the price a daily-wear compression garment needs.

We could market our stretch pieces as fully bio-based and let the small print do the explaining nobody reads. Instead: every product page states the exact percentage, because a 93/7 blend is a specific, defensible decision, not a compromise we're trying to talk around. Elastane is the reason a compression tee holds its shape through a training session instead of sagging by the second set. That function matters enough to include, in the smallest amount that still does the job, alongside materials that do everything else the garment needs without needing to be synthetic at all.

Most brands making bio-based claims either ignore this problem or bury it. We'd rather name the exact number and let it hold up to scrutiny, because a claim you have to hide from your own customer isn't one worth making in the first place.