Rayon From Bamboo Fiber Polyester Blend Sheet Set. Crafted with a smart 55% rayon from bamboo fiber and 45% polyester mix. while the polyester keeps them strong, preventing pilling or stiffening even after repeated washes. Whether it’s sweltering July nights or crisp December mornings, they can chase away heat, gently insulating when temperatures drop, so you stay cozy all year without swapping sets. Easy Care, just cold water, mild detergent (no bleach needed), and a quick hang-dry.