In the fast-growing next-gen materials market, cellulose fibers extracted from wood, old textiles, and even bacteria are performing akin to cotton, silk, and polyester. This offers an exciting opportunity to alleviate environmental problems caused by incumbent fibers, and at the core of this movement are man-made cellulosic fibers (MMCFs). For now, the transparent, environmentally and socially sustainable sourcing of MMCFs relies on quantifiable data from the likes of TrusTrace, GreenStory, and the Textile Exchange, among others. The focal takeaway regarding this fast-growing market is that not all MMCFs are created equal, and Challenge The Fabric certainly lived up to its name. An ongoing dialogue with the forestry and pulp industry is necessary to optimize and shed light on the calculable environmental and social benefits of MMCFs, to expand the market whilst safeguarding Earth and humanity.