Glossary

Box spring: 
The term "box spring" is often used interchangeably with "foundation," but these are two different things. What makes a foundation different from a box spring is that a foundation is produced without moving parts or springs. This construction provides the proper durability to support today's single-sided mattresses which are designed to provide the same comfort and support as a two-sided mattress, but without the need to flip the mattress.

Coils:
Spirals of steel wire that make up an innerspring unit—or the support system—of an innerspring mattress.

Coil count:
The number of coils in an innerspring unit. A high coil count alone does not indicate better quality. Firmness, support, and durability are determined by the design of the coil, the gauge of wire used, and the way the coil is engineered. The count is usually based on the number of coils in a queen-size unit.

Comfort layer:
The upholstery and quilt layers of a mattress, typically composed of various foams and fibers, that rest on top of the support system. The comfort layer determines the feel or firmness of a mattress. May also be referred to as an upholstery layer.

Euro-top mattress:
A type of mattress with an additional upholstery layer at the sleep surface for enhanced cushioning. It has more structured tailoring than a traditional pillowtop and, therefore, can be constructed to feel firmer than a pillowtop.

Firm mattress:
A type of mattress with a construction that uses less foams and fibers so the sleeper sleeps closer to the support system and feels less cushioning.

Foam density:
The weight of one cubic meter (foot) of foam. Foams with a higher density have better durability, which is why Serta uses a 5-lb memory-foam core in its specialty products.

Foam encasement:
Hard-form rails along the perimeter of a mattress used to protect against edge breakdown. Mattresses with foam encasement experience less edge sagging and have an extended sleep surface.

Foundation:
Provides durability for today's single-sided mattresses. The term "foundation" is often used interchangeably with the term "box spring." However, these are two different things. What makes a foundation different from a box spring is that it is produced with no moving parts or springs. This construction provides the proper durability to support today's single-sided mattresses which are designed to provide the same comfort and support as a two-sided mattress, but without the need to flip the mattress.

Mattress ticking:
The fabric that makes up the cover of the mattress. Serta mattresses feature a variety of covers—from traditional damask to cotton—all of which offer a variety of unique, value-added benefits.

Pillowtop mattress:
A type of mattress with an additional upholstery layer at the sleep surface for enhanced cushioning. Its tailoring is less structured than a Euro-top mattress, which also has an additional upholstery layer.

Plush mattress: 
A type of mattress with a construction similar to a firm mattress, but with enhanced cushioning at the top of the mattress for a softer feel.

Pressure points:
Serta offers many advanced features that help reduce pressure points.

Support system:
The innerspring or foam core center of a mattress which provides support. Various types of both innerspring support systems and foam core supports systems are available in today's market.

Ultra cushion-top mattress:
A mattress top like a pillowtop that uses two tape edges instead of one, allowing more upholstery layers to be added.

Visco-elastic memory foam:
A temperature-sensitive, slow-recovery urethane foam that conforms to the body and distributes pressure according to body heat and weight. It comes in many thicknesses, densities, and different levels of softness and firmness. Visco foam may be used as the primary construction material, or as a component of the comfort system of an innerspring mattress.

Information provided by Serta.