Clean Climber is an organization that is committed to making climbing more sustainable. They do this, among other things, through clean-up campaigns and the reuse and re-soling of climbing shoes. In several bouldering halls you can donate worn climbing shoes for recycling.
Climbing gear is often left behind in climbing and bouldering halls. These clothes are often no longer collected. Clean Climber approached us if it was possible to make mouth caps from this clothing.
After some consultation, we came out to make mouth caps from leftover (and washed) t-shirts. A prototype was successful and we started recycling these t-shirts into mouth caps.