A mattress covering is an important part of a bedding set. It consists of two components: a SHEET and a foampad. A SHEET is a flat piece of fabric that is placed over the mattress and tucked in at the sides. It is usually made of cotton, linen, or polyester. A foampad is a thin layer of foam that is placed on top of the SHEET to provide extra cushioning and comfort. Both the SHEET and the foampad are essential components of a mattress covering.