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Term Definition

A generic term to describe any platform or other support system meant to support a mattress or increase the height of the sleeping surface. There are many types including boxsprings, slatted bases, wire grid bases, bunkie boards, foundations, platform beds, solid surface bases, and many others.

Body Impression

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.

Buckling Column Gel
Is a newer material used in comfort layers which has some unique properties. It is not commonly seen although some recent changes in ownership and licensing have made it more available and it may become more widely available yet over time.