Vegetable-tanned leather vs TPU: carbon origin, greenwashing rules, and how heavy leather is made

An article from Lampoon Magazine follows Cuoio di Toscana's He(ART) capsule with designer Paul Andrew and uses it to explain how heavy leather is made. The process starts with hides from the meat and dairy supply chain, then soaking, liming, and vegetable tanning with chestnut, mimosa, and quebracho extracts. The piece also covers the legal definition of leather in Italy and where imported hides come from. The more useful part for sustainability readers is the comparison between a vegetable-tanned leather sole and a TPU sneaker sole marketed as vegan. A radiocarbon study commissioned by Cuoio di Toscana found the leather sample was mostly biogenic carbon while the TPU was fossil-derived. The article is careful to note that biogenic carbon is not the same as a full lifecycle assessment, and it cites EU rules banning generic environmental claims.