A good quality mattress can cost hundreds or even thousands of dollars. It should last twenty years. Protecting that investment is the job of mattress covers.
Mattress covers are an inexpensive way to protect your mattress from body fluids, spills, and allergens. You can buy simple ones that only offer protection, or you can buy more involved ones that also add another layer of comfort and cushion to your mattress.
Mattress covers are similar to mattress pads; indeed, the terms are often used interchangeably. The difference is often just a matter of the intended use. A mattress pad is considered something that makes a bed softer. A mattress cover is for protection. Typically, a mattress pad covers only the top and perhaps the sides of a mattress, while most mattress covers completely enclose the mattress.
The simplest mattress covers are just zippered bags that enclose a mattress. They are supposed to keep dust from infiltrating the mattress. These mattress covers provide no protection against allergens that form inside of the mattress, and they do not protect the mattress against bedwetting accidents.
Absorbent or waterproof mattress covers are designed to keep mattresses from getting wet. This type of mattress cover consists of three main layers. The top layer wicks moisture away from the sleeper into the inner layer. The inner layer -- actually, from one to as many as four layers -- is a highly absorbent fiber material that absorbs up to two liters of water. This inner layer may be cotton fiber or polyester. Hemp fiber (which does not contain any active ingredients of marijuana) is a popular filler; it's softer than cotton and can absorb twice as much water. The bottom layer is polyester, vinyl, or some other waterproof material that acts as a barrier between wetness and the mattress.
Some mattress covers are made from wool shorn from sheepskin and sewn to a polyester or cotton backing. Sheepskin mattress covers allow air to circulate under a sleeper, keeping one cool in warm weather and warm in winter. Sheepskin wool's ability to wick moisture away from the skin also plays a role in this type of mattress cover's popularity.
Dust mite mattress covers are designed for people with allergies. Dust mites are tiny bugs that breed in mattresses and other dark places. They live on bits of skin that people shed while they sleep. Dust mite droppings and the particles of their dead bodies are significant triggers of allergic reactions. Dust mite mattress covers are often made from impermeable materials such as vinyl or polypropylene, both to cut down on dust mite infiltration and to prevent the release of dust mite allergens when a sleeper rolls over.
One other type of mattress cover is worth mentioning. When it's time move your household, you do not want to throw a thousand-dollar mattress into the back of a moving van, unprotected. Professional movers bring along mattress covers made especially for moving. Do-it-yourself moving van rental companies will sell you a mattress cover for under five dollars. This type of mattress cover is nothing more than a heavy-duty polypropylene bag, open at one end to received the mattress or box spring. Just slide it on, tape it shut, and you won't have to worry about your mattress getting dirty during a move.
Mattress covers not an essential bedding item in all cases. But they come in very handy for keeping mattresses nice and clean.