MATERIALS & CARE SLIPPERS, SANDALS, AND OTHER NON-RUBBER FOOTWEAR: Our footwear is made from high quality materials and textiles. To clean a non-rubber item, we recommend gently spot-cleaning with a lightly damp cloth. RUBBER BOOTS: Did you know rubber comes from trees? The process of making handmade boots involves mixing limestone and rubber to give the footwear its form. It’s natural for quality rubber to develop a white film, called blooming, and it’s easy to clean.