Mattress Glossary




Adjustable Air Mattress: Uses air, rather than a coil system or foam core, for support. Air chambers running through the mattress allow sleepers to adjust and customize their comfort. 


Allergen: A substance that causes an allergic reaction.


Antimicrobial: Fabric that prevents or inhibits the growth of microorganisms. 




Bamboo Fabric: A very soft, breathable, and durable antimicrobial natural fiber made from the pulp of bamboo plants. Bamboo fabric absorbs and wicks away moisture to contribute to a more comfortable sleep environment


Bed Frame: A metal frame that holds the foundation and mattress in position and connects to the headboard and footboard.


Bedding: A broad term that describes the mattress, linens, and other items that make up a completed bed.


Body Impressions: The result of upholstery layers wearing and settling in a mattress. Body impressions are normal and typically dissipate over time.


Bonnell Coil: A basic innerspring mattress coil that has a round, hourglass shape. Individual coils are held together by metal strings known as helical lacing.


Border Wire: A strong wire that connects the coils around the perimeter of the mattress to provide edge stability.


Box Spring: (also called a foundation) A unit containing springs or metal rods that support the mattress. 




Cal King: A mattress size measuring 72" x 84". 


Coil: Supportive springs found in innerspring mattresses. Coils work together in a system to provide support in the mattress.


Coil Count: The number of individual coils in a mattress.


Coil Gauge: A measure of the thickness of individual coils in a mattress.


Coil Configuration: The arrangement of coils in a mattress.


Comfort: A description of the way a mattress feels, considering the ability of the cushioning materials to conform to the body's shape.


Continuous Coil: An innerspring coil system that is made from one piece of wire. 


Contouring: The ability to fit the shape of a sleeper's body.


Convoluted: A common foam configuration featuring peaks and valleys. 




Density: The weight per cubic foot of foam. Density an important indicator of the overall quality of foam. A higher density usually means greater durability. 


Double Bed: See Full Size 


Dust Mites: Microscopic creatures that can live in a mattress and feed on dead skin cells. As many as a million dust mites can live in a mattress, and they are a common trigger of asthma and allergies. 




Edge Support: Either a border rod or foam encasement that delivers extra support to the perimeter of the mattress to enable uniform comfort and support. 


Egyptian Cotton: Fine cotton woven with the longest, softest, and strongest fibers, resulting in the most luxurious fabric and feel.


Euro Top: Extra padding layered on top of a mattress to provide additional softness. Euro tops are like pillow tops, except that they are sewn to sit flush on top of the mattress. 




Firmness: A description of how much resistance a mattress applies to body weight and the resulting give of the mattress surface.


Foam: A material made from polyurethane or latex. Foam can provide a wide range of comfort levels, from cloudy soft to rock hard.


Footboard: A board or panel that connects to the foot of a bed frame.


Foundation: see Box Spring 


Full Size: A mattress that measures 54" x 75". Also referred to as a double. 




Gusset: A squared-off edge of a pillow, comforter, or upholstery layer. Gussets can add strength to the edges and corners of an upholstered product. 




Hand: The feel of the material as the hand is rubbed lightly over the surface. 


Hardness: A measure of a foam's ability to support a load. If the foam is too soft, it will bottom out. If it is too firm, it won't contour properly.


Heat Tempering: A process in which coils are heated with electricity to give them a permanent memory. Tempering allows the coils to return to their original height over time and numerous compressions. 


Headboard: A board or panel that sits at the head of a bed.


Helical: A small, spiral-shaped wire used to connect coils in an innerspring unit. 


High Density (HD) Foam: Foam that is especially dense and durable.


High Resilience (HR) Foam: High-quality foam that offers superior resilience, comfort, and durability.


Hybrid Mattress: A mattress that combines foam and innerspring support systems to offer sleepers the benefits of both an innerspring and foam mattress.


Hypoallergenic: A term that describes objects and material that does not provoke an allergic reaction. 




ILD (Indention Load Deflection): ILD measures how much weight it takes to compress a sample of foam by 25% (or to 75% of its original height or thickness). 


Innerspring Mattress: A mattress that uses metal coils as its support system.


Independent Coils: Coils that work independently of each other to limit the transfer of motion and disturbance from one sleeping partner to another. 




King Size: A mattress that measures 76" x 80". 




Latex Foam: A natural and antimicrobial foam that provides durability, support, and resilient comfort. 




Memory Foam: Visco-elastic polyurethane foam that has both viscous and elastic properties which make it ideal for both support and comfort in a mattress or other furniture products.


Motion Separation: Limiting how much motion is felt from one side of the mattress to the other. 




Natural Fibers: Fibers that come from a plant or animal, such as cotton, wool, silk, or bamboo. 




Offset Coil: An innerspring mattress coil that has squared edges to provide more flexibility and enhanced body contouring.


Open Coil: see Bonnell Coil


Open Cell Structure: A permeable structure in flexible foam in which there is no barrier/film obstructing the passage of air through the cell windows. Open-cell foams allow air to pass through and aid a mattress in regulating body temperature.






Pillow Protector: A covering for a pillow that protects it from dirt, oils, and moisture.


Pillow Top: A mattress design that features an extra layer of comfort padding on the surface of a mattress. Pillow tops provide a softer feel without diminishing the support. 


Plush Top: Similar to a pillow top in feel, but the extra layers of padding are less visible because they are built into the surface rather than layered on the top.


Pocketed-Coil: Exclusive and proprietary design of Simmons Bedding Company. Flexible high carbon coils enclosed in a flexible fabric pocket to relieve pressure and block the transfer of motion between sleeping partners.


Polyurethane Foam: A flexible, durable, and resilient material used in a variety of products for cushioning. Aside from natural latex foam, all mattress foams are polyurethane foams. 


Pressure Points: Areas of the body that bear the most weight and pressure when lying down. Without the right contouring support, pressure points can cause discomfort and numbness, resulting in tossing and turning.




Queen Size: A mattress that measures 60" x 80".


Quilt: The outside cover on the top of a mattress. 




Resilience: The ability of a foam surface to spring back to its original shape. Often described as "springiness". 






Sleep Set: A general term used to describe the combination of a mattress and foundation.


Support: A general term used to describe how a mattress distributes and stabilizes body weight and maintains proper body alignment.


Synthetic foam: A polymerized cellular material made from an organic base other than rubber.


Synthetic Fibers: Man-made fibers such as polyester and acrylic.




Ticking: The outer covering of a sleep set. The protective fabric cover encases the support and comfort layers of the mattress.


Tight Top: A mattress without a pillow or euro top.


Twin Size: A mattress that measures 39" x 75". Also called a single.


Twin-XL: A mattress that measures 39" x 80". 


Thread Count: A measurement of the number of threads per square inch of fabric. Generally, a high thread count results in a finer, smoother weave.




Upholstery Layers: The foam and padding used between the support system and the cover of a mattress.




Visco Elastic Memory Foam: See Memory Foam




Wrapped Coil: See Pocketed Coil. Wrapped coils are the same as pocketed coils. This term is used by all manufacturers except Simmons Bedding Company.