This is the best mattress pad I have ever purchased. The mattress top is a high quality jacquard cotton. The sides are thin stretchy fabric, not that smocked papery stuff so many other pads have. The pads easily fit a 13" deep mattress, probably can go up to 15" but I doubt any deeper than that. The pads wash very well too. My only complaint is that they are the perfect size out of the package and when washed the top shrinks slightly. If they made the pad top just 1" larger in width and length it would solve that problem. But despite the flaw, this is still the best mattress pad out there.