Mattress pads come in a variety of materials. The cover of a mattress pad can be cotton or soft pima cotton, sateen, bamboo top, polyester, microplush, microfiber, or wool. A sateen mattress pad has a soft and sheen feel. A bamboo top mattress pad is silky and diffuses body heat. The microplush mattress cover is covered in fine velvety, acrylic fibers which are easily washed, unlike velvet. Microfiber makes for soft, fine fabric which retains heat and dries quickly, increasing the comfort and durability of the mattress pad. Wool traps air and gives the mattress cover insulating properties which regulate temperature. In addition to the material of a mattress cover, its weave or pattern also determines its feel. The pattern of a mattress cover holds the fill in place and retains its shape. Quilted top mattress pads feature multiple layers in a diamond, wave, or square pattern. Pillow top mattress pads feature billowy tops that simulate the feel of a pillow. A deep pocket mattress pad has deep fitted pockets for a secure fit. The filling of a mattress pad is generally hypoallergenic synthetic and down alternative fibers such as polyester, cluster fiber, or gel fiber. A thick type of mattress pad is a fiber bed, which is hence more of a mattress topper, yet shares the properties of a mattress pad. It is a mattress topper which can have the clinging skirt of a mattress pad or lie separate. A mattress protector fully encloses the mattress and is designed to protect against allergens, dust, and bed bugs.