Pukka Herbs
Pukka set the bar for a truly plastic-free bag. The filter is a blend of abaca (banana fibre), wood pulp, and plant cellulose, and instead of a heat-seal, staple, or glue, Pukka folds the bag and stitches it shut with a length of organic cotton thread - the string and the seal are the same piece of cotton. The paper is cleaned with an elemental-chlorine-free oxygen process. Independent lab testing (Mamavation) found non-detect fluorine on the bag, and Pukka's bags carry a UK home-compostable certification.
As with everyone, the individual overwrap is the weak point - a mostly-paper envelope with a thin plastic coating for freshness - but it never touches the tea.
How clear are their specs?
Publishes the bag fibre blend, the fold-and-stitch (no staple, no glue) construction, and the organic-cotton thread, and backs the plastic-free claim with home-compostable certification.