While advertised as Bamboo, and Rayon, the actual fibre content is a 60%/40% polyester and bamboo/rayon blend.
Also, the dye from these bleeds like nothing I have seen in years! Several hot washings to get the excess dye out, several saturated 'colour catcher' washing cloths, and they still bleed purple. 
The elastic on the bottom sheet is much much too soft and delicate to hold the sheet on. 3 strikes, and they are out. If you don't mind synthetic sheets, and buy a light colour, well, you'd still have to re-make your mattress   corners every time you get out of bed.