Microfiber is a performance fabric that is expertly woven for luxury, softness and easy care. It can be made of wood pulp, nylon or polyester.  
In reference to the dimensions of the mattresses that our bedding covers, “California King” is longer than King and should only be purchased if you have a California King sized mattress. King and Eastern King are two names for mattresses of the same dimensions (some people just use different terminology). Our Duvet covers and blankets have been made in a universal size, so they fit both King and California King mattresses.