"Wamsutta's Zen Comforts is a soft, luxurious fusion of bamboo and cotton. Bamboo fibers are as soft as silk and naturally breathable, and are an eco-friendly fiber. It feels very similar to other wood-based fibers that you may be more familiar with (Rayon, Tencel and Modal for example). It is durable but still exquisitely soft. 60% bamboo, 40% cotton300 thread count the fitted sheets fit mattresses up to 18" deep4" hem with self piping on the flat sheets and pillowcasesqueen set comes with standard cases, king and cal king come with king casesplease note, the ivory tone is darker than a typical ivory and the white is not bright white, it is an off-white machine wash in cold, tumble dry on lowThis style has been discontinued. Stock is limited to the items and colors listed below."