The boxers are partially made from modal (45%), cotton (50%) and elastane (5%). Modal is biodegradable and eco-friendly because of its natural content. It’s made from the cellulose of the beech tree and it sustainably harvested. The beechwood cellulose is mashed into a liquid, turned into a fiber, and woven into a fabric. All trees and plants are made up of cellulose and they can (re-)produce more of it, thereby renewing themselves and enabling a sustainable harvest.