Glossary

A mattress support system that is either tension adjustable, height adjustable, or position adjustable. The most common of the adjustable bases is an adjustable bed that can raise and lower the legs and torso either for leisure activities such as reading or watching TV or for health reasons such as snoring, acid reflux, pressure relief, or circulation.

The permanent impressions in a mattress that often develop after repeated use over time. It is called a body impression as it forms in the shape of your body with the deeper impressions usually under the heavier areas. With natural fibers used in a comfort layer, it is an expected and desirable process as it is part of how these materials form a cradle and relieve pressure. With foam materials it indicates foam breakdown and the permanent loss of some of the foam's properties. Synthetic fibers like polyester used in comfort and quilting layers can also make a significant contribution to body impressions as they compact and become firmer over time.

Similar to an innerspring except it generally uses fewer and stronger coils or torsion springs and is used under an innerspring mattress to support it, protect it from sudden shocks that can damage the innerspring, and to help it's its ability to respond to weight and provide additional pressure relief or improve alignment. Some innerspring mattresses are made to work with specific boxsprings as part of their design.

The ability of a material to allow air to flow through it. This is an important part of sleeping comfort and temperature regulation. Foams that have cells that are less open are also less breathable.

A subjective feeling that is the result of many interacting factors. While it is often used to mean pressure relief, this can be misleading. The most important parts of the perception of comfort are ILD, support factor, resilience, hysteresis, hand feel (surface compression), point elasticity, pressure relief, and spinal alignment. -

Another term for Support Factor.

Another term for support factor.

How long a material will keep its desirable properties and used also to indicate how long a material will take to completely break down.

This is used to prevent a mattress from bursting into flame and preventing "flashover" from either a smoldering heat source or with an open flame.