Mattress

A mattress is a large, typically rectangular pad that supports a person lying down, primarily for sleep. It can function as a bed on its own or sit on a bed frame as part of a bed system. The mattress itself often consists of a quilted or fastened case made from heavy cloth, filled with materials like hair, straw, cotton, foam, rubber, metal springs, or even air or water. It usually rests on a bed base, which might be solid (as in a platform bed) or elastic (like a box spring or slatted foundation). In Europe, a divan combines both mattress and foundation into one upholstered, footed unit; divans contain at least one innerspring layer plus cushioning, and may come with a secondary mattress or removable topper. Mattresses can also be filled with air, water, or natural fibers—futons are an example, kapok is common in Southeast Asia, and coir is used in South Asia.

**History** A third-century BCE papyrus mentions a man named Krotos waiting in Jaffa to export mattresses. The word "mattress" comes from the Arabic *maṭraḥ*, meaning "something thrown down" or "place where something is thrown down," hence "mat" or "cushion." During the Crusades, Europeans adopted the Middle Eastern practice of sleeping on floor cushions, as beds there were reserved for the wealthy. The term *materas* later entered Middle English through Romance languages. The oldest known mattress, dating to about 77,000 years ago in South Africa, was made from layers of twigs and leaves—including *Cryptocarya woodii* leaves, which naturally repel insects and likely helped ward off mosquitoes. Early mattresses used straw, feathers, or horsehair. In the first half of the 20th century, North American mattresses typically had an innerspring core and cotton batting or fiberfill. Modern mattresses often contain an innerspring core or materials like latex, viscoelastic, or other flexible polyurethane foams. Other fill components include insulator pads over coils (to prevent upholstery from cupping into the innerspring) and polyester fiberfill in top layers. In 1899, James Marshall introduced the first individually wrapped pocketed spring coil, now called Marshall coils. Today, the typical North American mattress is innerspring, though all-foam and hybrid beds (combining innerspring with high-end foams like viscoelastic or latex) are gaining interest. In Europe, polyurethane foam and latex cores have long been popular and make up a larger share of the market.

**Sizes** Mattresses are made to fit bed sizing standards that vary by country. Dimensions differ in width, height, and depth across national standards. Many markets use non-numeric labels like "King," "Queen," "Double," "Full," or "Single" to indicate size.

**Mattress Topper** A mattress topper is a thin mattress, usually 5–10 cm (2–4 in) thick. Stand-alone mattresses of this thickness exist (such as futons or floor beds; traditional European beds were stacks of such mattresses). However, toppers are typically sold for use on top of box springs, secured with straps or elasticated corners. They extend the life of a more expensive box spring, adjust bed temperature (via airflow or heat-conductive materials), soften a firm bed, and are portable for travel or dorms, especially if low-density. Unlike a mattress protector or pad (a thin, usually unpadded layer not meant to improve comfort), toppers can also protect the mattress from the sleeper or vice versa. Some toppers are machine-washable; covers and fillings come in various materials.

**Types**

*Tick Mattress* A tick mattress is a bag made of ticking cloth filled with material. Examples include a paillasse, a featherbed, and most futons. These are simply constructed and were traditionally homemade. Because they are thin and light, they are layered to form a bed.

*Innerspring* Innerspring mattresses typically consist of a spring core plus top and bottom upholstery layers. The core supports the sleeper’s body. Modern spring cores, called innersprings, are made of steel coil springs (coils). Coil gauge is one factor determining firmness and support; coils are measured in quarter increments, with a lower number meaning a thicker spring. Higher-quality mattress coils generally have a 14-gauge (1.63 mm) diameter. Coils of 14 to 15.5 gauge (1.63 to 1.37 mm) give more easily under pressure, while a 12.5-gauge (1.94 mm) coil—the thickest commonly available—feels quite firm. Connections between coils help the mattress retain its shape; most coils are linked by interconnecting wires, while encased coils are not connected but rely on fabric encasement. There are four types of mattress coils: - **Bonnell coils** are the oldest and most common, adapted from 19th-century carriage seat springs and still used in mid-priced mattresses. They are knotted, round-top, hourglass-shaped steel wire coils laced together with cross wire helicals to form the simplest innerspring unit (a Bonnell unit). - **Offset coils** are hourglass-shaped coils with flattened portions on the top and bottom convolutions.