CEDR
CEDR exists specifically to answer the "0 synthetics" request. Every style is a single natural fiber or a natural-fiber blend - GOTS organic cotton, RWS merino wool, mulberry silk, or European flax linen - and the waistband stretch comes from certified natural rubber knitted into cotton rather than elastane. There is no polyester or spandex in the fabric or the band, which is rare for a brand offering this many non-cotton options. Natural rubber is a latex, the usual caveat.
How clear are their specs?
Names the fiber and certification for each style (GOTS cotton, RWS merino, mulberry silk, European flax linen) and states the waistband is natural rubber wrapped in organic cotton with no synthetics.
