The shoulder straps, back pads, and other exterior materials and accessories, such as zippers, used in our backpacks are all biodegradable, breaking down naturally into harmless substances. Natural materials include cotton, linen, and bamboo. The exterior fabrics used in our backpacks, such as canvas and cotton-linen, are environmentally friendly and breathable. Other stationery plastics, such as PP, PS, ABS, TPR, and HDPE, can be recycled and reused to make rulers, desk organizers, and clipboards, reducing pollution.