Mattress Glossary

When researching for a new mattress it easy to get confused by the jargon and many different terms used in the mattress industry. We have put together a glossary of the most common words and terms you may come across when researching a mattress.

Adjustable Bed – A bed that can achieve different positions through mechanized and non-mechanized means. An adjustable mattress can be set in an upright position or can be adjusted to raise the feet.

Air Flow – Amount of air expressed in cubic feet per minute (cfm), that can be drawn through a 2″ x 2″ x 1″ FPF sample at .5-inch water pressure differential. A cfm of 2.0 and above is considered good for flexible polyurethane foam.

Air Mattresses– Air Mattresses use an air chamber instead of springs to provide support. Quality and price can range from very cheap to the ultra high end. When comparing to innerspring mattresses the price is generally higher. Recent innovations to air beds include the ability to adjust the firmness of the mattress.

Alignment – The proper position and balance of the spine. A supportive mattress aids in proper spinal alignment and can help alleviate backaches. Usually lying on one’s side is the best way to maintain proper spinal alignment.

Anti-Bacterial– Commonly used in the textile industry on fill material for pillows and mattress pads, antimicrobial agents are capable of destroying or inhibiting the growth of bacteria.

Anti-microbial– Commonly used in the textile industry on fill material for pillows and mattress pads, antimicrobial agents are capable of destroying or inhibiting the growth of mold, mildew, and bacteria.

Bed Frame – A frame that supports the mattress and its foundation. For full, queen and king mattresses, it is recommended to use a frame with a center support that extends the entire length of the mattress.

Blended Latex– Type of Latex produced from a blend of natural and synthetic latex. Often claimed to combine the Elasticity of Natural Latex with the consistent quality and Durability of Synthetic Latex.

Body Impressions – Minor indentations formed on the surface of the mattress resulting from comfort layers contouring to the sleeper’s body. To refresh the comfort layers, rotate your mattress monthly.

Body Pressure Points – Areas on the body where pressure builds up, typically the shoulders and hips. The result is uncomfortable pain or numbness that causes a sleeper to toss and turn. Tossing and turning does not result in a restful sleep.

Bonded Foam– Foam particles or shredded foam (often manufacturing scrap) that has been glued to form a useful product. The resultant FPF block is peeled into the desired thickness. Largest use is for carpet cushion.

Bonding – The combination of two or more components into a multiple-layer composite. In furniture applications, FPF is often adhered to other FPF grades or to polyester fiber.

Bonnell Coil– The oldest coil in the industry still used in less expensive mattresses. These hour glass shaped coils were first adapted from buggy seat springs of the 19 century. 

Border – The term used to describe the side or perimeter of the mattress. (Insert Pic)

Border Rod (Border Wire)- A wire used around the perimeter of a mattress to help the innerspring maintain its structural integrity, while also helping create a firmer edge for sitting.

Bottom Out – Lack of support under full weight load.

Box Spring – The bottom piece of your sleep set. It is usually a foundation made of wood and steel, designed to support a mattress. It is recommended to replace your box spring when purchasing a new mattress.

Box spring– A type of Foundation, usually consisting of heavy Coils mounted on a wood frame with no padding, designed to support an Innerspring Mattress. Often referred to as a Set when offered with a mattress.

Box top – A type of mattress where the top layers of foam are made into what is essentially a mini-mattress and then attached to the base part of the mattress in a pillowtop fashion via a gusset and inner panel. Usually found on very plush mattresses that contain multiple layers of plush padding material or a secondary micro-coil innerspring unit.

California King– Mattress size that measures 72″W by 84″L. Slightly narrower and longer than a standard King, which measures 76″W by 80″L.

Coil Count– The number of coils found in an innerspring mattress, this helps determine the support of the mattress.

Coil Gauge– The gauge of a coil is the thickness of the wire that makes up the coil. The higher the number the thinner the wire, the lower the number the thicker the wire. The gauge of a coil is determined by the amount of wires you can fit side by side in a linear inch.

Comfort Factor– The Comfort (Support Ratio) is the ratio of 25% to 65% of ILD readings. A good comfort factor is between1.8 to 3.5

Comfort Layers – The quilting and upholstery layers that determine mattress comfort. The thickness, types of foams and fibers, and the order in which they are combined all have an effect.

Comfort Life – The length of time a mattress will provide proper support and maintain comfort relative to the original feel.

Comfort: Foam – The ability of the cushioning structure to deflect at the surface and to conform to body shape, preventing a concentration of pressure on the body.

Comfort: Mattress – An individual’s preference based on the feel, support and conformance of the mattress. Many factors affect comfort, like the sleeper’s weight and sleep position, the environment and the mattress construction.

Conformance – The response to a sleeper’s body. Optimum conformance is achieved when the sleeper has proper spinal alignment.

Continuous Coil – An innerspring construction in which each row of coils is made from one piece of wire that is woven into a grid network. (Show Pic)

Convoluted foam– Egg crate shaped foam (with hills and valleys) that provides a plush feel and helps to distribute body weight more evenly. Commonly used in hospital beds to reduce pressure points on hips and shoulders while stimulating even blood circulation.

Core – The support system inside a mattress: typically an innerspring unit or foam. (insert Pics)

Corner Guards – A plastic or metal fitting attached to the four corners of the foundation for protection. (Insert Pics)

Cover – Also known as ticking, it is the fabric surrounding the mattress.

Cradling – The ability of the cushion system to distribute body weight uniformly over the seating area.
Crown- Condition wherein a mattress is slightly higher in the middle than on the sides, creating a convex surface.

Damask – A mattress cover that features a design woven into a thick fabric. Belgian and Jacquard are two types of premium Damask fabrics.

Density – A measurement of the mass per unit volume. It is measured and expressed in pounds per cubic foot (pcf) or kilograms per cubic meter.

Double Bed – Another name for a full or standard size mattress. Measures 54″ x 74″.

Dunlop Process – The old-style process of making latex, where the foam is mixed and poured into a mold where it hardens and is then sliced into sheets.

Dunlop– Process in which liquid Latex is “whipped” with air until it becomes wet Foam, at which time it is poured into a mold, hardened, and vulcanized. Tends to result in slightly firmer and heavier latex than the Talalay process.

Durability – How well an foam retains its comfort, support and shape with use. Most measures of durability are done with laboratory-scale tests.

Durability– Term that refers to the length of time a mattress will continue to provide you with adequate Support along with your desired level of Comfort. See our Durability Guide to determine the appropriate durability requirements for you.

Edge Guard– Plastic piece mounted onto the edge of the mattress that provides additional support to the mattress sides and protects the Cover from damage.

Elasticity– Term that describes the flexibility and Resiliency of an object or material.

Euro-top– Layer of additional padding sewn on top of a mattress. Similar to a Pillow-Top, but attached more firmly to the mattress.

Eurotop – A small extra side panel added to the top of a mattress via an additional tape edge to allow extra padding material to be added to the mattress while minimizing roll-off. Padding is carried to the edge of the mattress to create a squared-off appearance. Differs from a pillowtop in that a eurotop does not contain an inner panel separator layer.

Fiber– (Either natural or synthetic) Top quilting layer in the padding of the mattress, that gives the mattress additional padding and the ability to breathe, thus increasing the comfort and durability of the foams.

Filled/Filler Foam – The addition of inorganic materials to foam such as marble dust, barium sulfate, silica or clay, to increase the density. Fillers are often added to increase the support factor. Filled polyurethane foam may be inappropriate for some applications if the polymer content of the filled foam is not sufficient for the intended application before fillers are added. The fillers are not chemically bonded into the foam polymer; instead, they are mechanically trapped within the molecular structure of the polymer. Filled foams with low polymer content or a high percentage of filler material tend to have less strength and durability.

Firmness – A general term used to describe a range of mattress surface feels. The four common firmness ranges are firm, cushion firm, plush and ultra plush.

Foam Density– The weight of a cubic foot of foam (1 ft.x1ft.x1ft. block), ranging from under 1 lb (low density) to over 3 lbs (high density). The higher the density of foam, the longer it will last and the heaver it will be, due to a density of polyurethane.

Foam Encasing – Additional foam support around the perimeter of the mattress that provides a firm sitting edge and expands the usable sleep surface, minimizing the feeling of roll-off when approaching the edge of the bed.

Foam Mattresses– Foam Mattresses use latex foam or visco-elastic (memory foam), instead of springs to provide support. Since foam varies in quality, prices can vary widely.

Foundation – See box spring.

FR Compliant – As of 2007, all mattresses manufactured and imported in the U.S. are required to pass the strict flammability guideline 16 CFR part 1633. Review the mattress tag to confirm compliance. For more information, visit the Consumer Products Safety Council.

Full Size – A mattress measuring 54″ x 74″.

Helicals– Spirals of wire used to secure adjacent rows of Coils in Innerspring Mattresses. Also used to attach rows of coils to the Border Rods.

Hog ring – A metal ring or staple used to attach the Cover edge and Insulation to the Innerspring Unit.


Hypoallergenic– Materials that have a deceased tendency to cause an allergic reasction in most people.

ILD (Indentation Load Deflection)– ILD or ILF is the foam industry’s unit of measure to express a degree of firmness. Measured by determining the amount of force (in pounds) required to compress the foam by 25% of its original height. IFD for mattress foams tend to fall between 10 pounds (softest) and 80 pounds (hardest). Also known as Internal Force Deflection (IFD).

Inner tufting – An extremely Durable method of attaching and combining layers of padding below the quilted Cover so as to prevent any shifting or settling of the padding.

Innerspring -The spring and wire part of an Innerspring Mattress, comprised primarily of Coils, Helicals and Border Rods.

Innerspring mattress – Refers to any mattress constructed around a Core of Tempered Coil Springs. The Innerspring Unit is typically surrounded by several layers of Upholstery in order to provide additional Comfort. This is the most widely purchased type of mattress on the market. Also known as a spring mattress. See our Innerspring Mattress Guide for more information on how to distinguish one innerspring bed from another, including details on each component of the innerspring mattress.

King – A mattress measuring 76″ x 80″.

King split – Bed that consists of two Twin Extra Long mattresses, each 39″ wide x 80″ long.

Knit – A type of mattress cover fabric that is knitted rather than woven and has a soft feel.

Laminating – The bonding of layers of foam and/or other materials together into a single composite. This may be accomplished through adhesives or through heat processes like flame lamination.

Latex– A very durable and resilient foam naturally derived from the rubber tree. It provides long lasting comfort as well as support, and is a breathable and naturally anti microbial material. May be used in the comfort and support layers of a mattress. Fun Fact: If you had a 1″ piece of latex foam and 1″ piece of standard polyurethane foam, over 10 years of use, the polyurethane foam would compress to 1/4″ while the latex would only compress to 1/2″, making it virtually twice as durable!

Memory Foam– A slow reacting, weight and temperature sensitive foam that contours to the individual shape of ones body. Used in luxury mattresses to provide a customized feel that aides in circulation, reduce pressure points and limits motion transfer. Also called Visco Elastic Foam. Fun Fact”: Created by NASA to absorb G-Force pressures in space shuttle seats. However NASA never did end up using it.

Motion Disturbance – A term used to define the movement one feels from their sleep partner getting out of bed or moving in bed. Many technologies work to minimize motion disturbance, including placing the mattress set on a solid platform bed frame.

Motion sepraration – Refers to the degree to which movements on one side of the bed can be felt on the other side of the bed.

Non-Allergenic– Generally not known to cause an allergic reaction in humans. Estimated to cause an allergic reaction in less than 1% of the population.

Non-Prorated Warranty – This type of warranty covers full repair or replacement of a defective mattress for the entire length of the warranty period.

Offset Coils– Offset coils have flattened sides to the top and bottom turns of the coil. Offset coils are superior to the standard round coil because they can laced more times than a completely round coil. This allows the coil to hinge, thus conforming to body shape. Offset coils are very sturdy, stable innersprings that provide supeior support and durability.

Open Cell Structure – A permeable structure in FPF in which there is no barrier between cells, and gases or liquids can pass through the FPF. Most cell walls have been ruptured to varying extent.

Pillowtop Mattress – A type of mattress that features an inner panel and gusset allowing additional layers of comfort to be added to a mattress. Generally used to help minimize foam travel of more thickly padded mattresses. Pillowtops do not guarantee extra comfort – they are strictly a method of mattress assembly. (See pic)

Plush – Describes a mattress with a soft feel.

Pocketed Coils– Pocketed coils are each wrapped in a fabric encasement and usually are tempered for additional strength. Some manufacturers pre-compress these coils, which makes the mattress firmer and gives the coil a memory. Pocketed coil support is very conforming and reduces the transfer of motion from sleeper to the next. (Insert Picture)

Polyurethane foam– The general name for foam padding that is used to provide comfort and comformability to a mattress. Polyurethane foam comes in a range of feels depending on the density and chemical composition of the material. Each manufacturer gives polyurethane foam a patented name to provide appeal and exclusivity to their padding layers.

Posturized – Refers to various types of additional support placed in the center of a mattress or Foundation to prevent Sagging.

Prorated Warranty – A warranty that does not cover the full purchase price or replacement value after a certain period of time.

Queen Size – A mattress measuring 60″” x 80″”.

Quilting– The embroidered design on the top of the mattress which binds fibers and foams together to prevent materials from bunching or shifting under the ticking. The quilting can also impact the overall feel of the mattress depending on the pattern design: tack and jump (insert image) vs Continuous (insert image) The tighter the quilting the firm the feel.

Recovery Time – A term referring to the amount of time it takes a specific foam to return to its original shape once pressure has been applied. Visco elastic memory foam has a slower recovery time, whereas the recovery of latex foam is almost immediate.

Recovery time – Term used to describe the speed (or lack of speed) with which a material (typically Foam) returns to its original shape after being compressed.

Resilience – Is the measure of springiness in the foam. It is measured by dropping a standard steel ball onto the FPF cushion from a given height and measuring what percentage the ball rebounds. Rebound heights of 40-70 percent of the drop height are common.

Rotate – To turn your mattress. It is recommended that you do so once a month to help renew the comfort layers and maintain optimum performance.

Single-Sided Mattress – A mattress construction that has been designed with only one sleep surface, eliminating the need to flip your mattress.

Sleep Set – A mattress and box spring.

Smooth top – Term used to describe a mattress cover that isn’t Quilted.

Spring Count – The total number of individual springs within a mattress. Commonly (but not correctly) referred to as the coil count.

Spring-on-Spring – A specific mattress construction that features an innerspring unit with a second similar or smaller innerspring unit placed on top.

Springs – Wire shaped into spirals to provide support and resistance when weight is applied. A spring consists of coils, or the individual turns within the spring. Commonly grouped together in innerspring units and used for support in mattresses.

Super single – Mattress size that measures 48″W by 84″L. Significantly wider and longer than a standard Twin, which measures 39″W by 75″L.

Support Factor (see Compression Modulus) – Support Factor is a ratio os 65% IFD.25% IFD. When the support factor is known, it can be used in conjunction with a known 25% IFD value to determine the 65% IFD value. Seating FPFs with low support factors are more likely to bottom out. Common FPF support factor ranges for the mattress indutry are 1.5 to 2.6.

Support Layer– The layer of the mattress that determines it support other wise known as the mattress core. The coils, foam, or air chambers.

Surface Firmness – The number of pounds of force necessary to indent an FPF sample by 25% of its original height.

Synthetic Fiber– Man made fibers that increase the breathabiltiy of the mattress

Talalay Process – A more modern way of making latex foam, where the liquid material is injected into a mold that is then vacuum sealed and flash frozen, then heated and cured. This creates a foam which is very consistent and easily produced in a wide range of ILDs (softness). Insert pic)

Tape Edge – A sewn seam along the edges of the mattress that attaches the top and side panels, and encases the comfort and support layers.

Tempuring– Treating metal with heat and/or electrostatic energy. This process strengthens metal and gives it a “memory” to return to its original shape time and time again. Coils that are tempered will have increased durability and resiliency.

Ticking– A strong tightly woven fabric used to make pillows and mattress coverings. Ticking can be made from natural and synthetic blend yarns which may include Rayon Belgian Damask, Cotton/polyester blend circular stretch knit, or Satin Jacquard.

Tight Top – A mattress type that does not have an inner panel and an extra gusset to contain the upholstery padding material.

Torsion bars – Heavy wire bars, typically bent in 90 degree angles, used in certain Foundations to provide support for an Innerspring Mattress. Generally more rigid than traditional Box Springs. Also known as torsion modules.

Tufting – Hand tufting pre-compresses the foam layers and support layers of a mattress by running a very stout cord through the entire mattress from the top quilt panel through to the bottom of the mattress. This helps prevent body impressions and helps create a more solid mattress.

Twin Size – A mattress measuring 38″ x 74″. Also referred to as a single.

Upholstery – These are the layers of foam and cushioning materials placed on top of the innerspring unit and beneath the quilt panel.

Voids – The undesirable formation of large cavities or pockets in a foam structure. Voids are usually caused by poor moldability or incorrect mold filling. In the case of foam buns, voids occur when then blowing and polymerization reactions are out of balance.

Warranty – A statement by the manufacturer that indicates under what terms they will fix and replace a mattress. Warranties can be either prorated or non-prorated.

Wool/Silk, Cashmere, Alpaca, Angora– Natural fibers that increase the breathability of the mattress, thus aiding in temperature regulation to keep the sleeper cooler in the summer and warmer in the wint

Zoning – A term used to describe areas on a mattress that have been reinforced with additional support or padding. Zoning is often found through the center third of the mattress.