Nanofibre is the most amazing fabric you will ever experience. Made via nanotechnology, nanofibre resists water and stains while retaining 100% of the natural feel of the fabric. Nanofibre is not a coating and will not wash out, so the product is long-lasting. This mattress pad is 100% polyester microfiber. It has a 100% polyester fill and a stretch fit polyester sidewall.