GENERAL
MATTRESS GUIDES
Mattress Glossary
To help you with your mattress "lingo," we have compiled this handy list of definitions for some of the mattress industry's most common terms.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Adjustable Bed
Type of bed distinguished by its ability to bend and elevate into upright or other positions. Sometimes referred to as an electric bed or hospital bed. See our Adjustable Bed Guide for more information on the various features and benefits of adjustable beds.
Air Bed
Type of bed distinguished by its use of an air-filled Core, rather than Coils, for Support. Depending on its purpose and price point, may be upholstered with Cushioning, Quilting and/or Ticking. Also known as an air mattress. See our Air Mattress Guide for more information on high-end upholstered air beds, and our Portable Air Mattress Guide for additional information on portable air beds.
Air Chamber
Term that refers to the air containment area of an Air Bed.
Anti-Microbial Fiber and Foam
Fiber or Foam that has been treated to prevent the growth of bacteria, dust mites, mold, and fungi.
Articulation
Term that refers to the bending of an Adjustable Bed. An adjustable bed with "two-point articulation" folds in two separate places, dividing the bed into 3 sections — head, foot and middle — each of which can be elevated and/or angled to achieve the desired position.
Batting
Several layers of Cotton Felt.
Bed Frame
A metal or wood frame used to support the mattress and/or Foundation. Usually comes with legs and wheels (known as castors) with a conventional height of 7 1/4 inches. All Queen and King frames must have a center support bar and center leg for proper support (and in some cases so as not to void the Warranty).
Bed Rails
The "L" shaped metal or wood sides of a Bed Frame that hold the mattress in place.
Bladder
Term that refers to the water containment area of a Waterbed 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
Indentations on the surface of the mattress resulting from the normal compression of mattress Quilting and Cushioning layers over time. Should not exceed 1 1/2 inches in depth. Often mistakenly characterized as Sagging.
Bonnell Coil
The original and standard Innerspring Mattress Coil design, characterized by hourglass shaped springs. Today, used primarily in lower-priced beds. See our Coil Guide to learn more about the various types of mattress coils and how to compare them.
Border Rod
The heavy wire that surrounds the perimeter of an Innerspring Unit or Box Spring, maintaining its shape by connecting the outer layer of coils to the ends of the Helicals. Also known as border wire.
Border Wire
See Border Rod.
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.
Built-Up Foundation
See Slatted Base.
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.
California Queen
Mattress size that measures 60"W by 84"L. Slightly longer than a standard Queen, which measures 60"W by 80"L.
Chintz
A fabric used to cover mattresses whose design is typically printed onto it.
Coil Count
Refers to the total number of Coils in an Innerspring Mattress. Often quoted as the amount in a Full (double) size mattress for purposes of comparing different models. See our Coil Guide to learn how to evaluate and compare coils across various mattresses.
Coil Springs
See Coils.
Coils
Spirals of wires that form the supportive Core of an Innerspring Mattress or Foundation. Specific coil designs include Bonnell, Offset, Marshall and Continuous, each of which comes in various sizes and Gauges. Also known as coil springs. See our Coil Guide to learn why coils are important and how to evaluate coils across different mattress models.
Comfort
Term that refers to the way the surface of the mattress feels against your body. On an objective level, can be thought of as the "hardness" or "softness" you feel when you press the mattress surface with your fingertips. Can also encompass other features such as Motion Separation and breathability. See our Comfort Guide to ascertain the right comfort attributes for you.
Comfort Layers
Layers of Upholstery surrounding the Core that give the mattress surface a comfortable feel.
Continuous Coil
An Innerspring Mattress coil design wherein each row of Coils is constructed from a single wire shaped into a series of S-shaped ringlets. The concept behind this design is that by attaching each coil to its neighbors, the Innerspring Unit will have improved strength, stability, and Durability. See our Coil Guide to learn more about the various types of mattress coils and how to compare them.
Continuous Quilting
Convoluted Foam
Foam shaped similar to an egg carton, giving it the more common name "egg-crate foam," used to provide additional surface cushioning. Creates softer feel than a flat slab of similar Foam, and can improve circulation by reducing Pressure Points.
Core
Term that generally refers to the underlying Support layer of a mattress, whether the Innerspring Unit, Foam Core or otherwise.
Cotton
A soft, breathable, natural Fiber used to make numerous items. In certain mattresses, can have a tendency to absorb moisture and compress over time.
Cotton Felt
A treated Cotton fabric that weaves thick cotton Fibers together, forming a compressed layer that is used in mattress Upholstery.
Cover
The fabric encasing the mattress. Also referred to as Ticking. See our Upholstery Guide to learn more about the key elements of mattress upholstery and how they differ across mattresses.
Crown
A mattress that is slightly higher in the middle than on the sides, creating a convex surface.
Cushioning
Layers of material that lie between the Insulation and the Quilting of an Innerspring Mattress. Cushioning materials include Latex, visco-elastic foam (better known as Memory Foam), Convoluted Foam (also known as egg-crate foam), Felt, Cotton, polyester, non-woven fiber pads, wool, goose down, or even silk and cashmere. See our Upholstery Guide to learn more about the key elements of mattress upholstery and how they differ across mattresses.
Damask
A thick fabric used for mattress Covers whose design is typically woven into the fabric rather than printed onto it. Certain types of damasks are considered particularly high quality, such as Belgian (softer, high thread count), matelasse (raised design), jacquard (made with special loom), and tapestry (extra heavy).
Daybed
Type of Dual-Purpose Bed consisting of a Twin mattress configured in such a way as to allow for easy use as either a seating or sleeping area. Typically enclosed by a Bed Frame on 3 sides, creating a sofa-like feeling when combined with pillows.
Deck
Refers to the top surface of a specially-designed Platform Foundation that supports the Frame of a Hard-Sided Waterbed. Together with the Pedestal below, evenly distributes the weight of the mattress, so as to minimize strain on the Bladder seams as well as the floor.
Density
Measurement of weight over volume, typically referred to in pounds per cubic foot. Considered an important characteristic of Foam mattresses that typically correlates with Durability, and sometimes (though not always) with Firmness.
Double Bed
See Full.
Double Ended Frame
Bed Frame that is compatible with both a headboard and footboard.
Double Extra Long
See Full Extra Long.
Double Heat Tempering
Type of Tempering process wherein Coils are heated, cooled, and then heated again, for additional Durability and Resiliency.
Dual-Purpose Bed
Reference to any sleeping device that has a secondary function. Examples include sleeper sofas, Futons and daybeds.
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
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 Break-Down
Term that refers the loss of Support along the outer edges of a mattress, commonly experienced in older beds. Can result in the sensation that one is rolling or sliding off the side of the bed.
Edge Coils
Additional or heavier Coils placed along the edges of a mattress to provide extra Support and protection against Edge Break-Down.
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.
Egg-Crate Foam
See Convoluted Foam.
Elasticity
Term that describes the flexibility and Resiliency of an object or material.
Electric Bed
See Adjustable Bed.
Euro-Top
Layer of additional padding sewn on top of a mattress. Similar to a Pillow-Top, but attached more firmly to the mattress.
Fatigue
Refers to the state of a mattress when it can no longer adequately Support a sleeper's weight. Typically results from a softening or compressing of the Coils.
Fiber
Strands of material, made from natural or synthetic elements, which are used extensively in mattresses. Fiber strands have air between them, meaning that fiber tends to compress over time.
Fiber Filling
Motion dampening materials, such as layers of Fiber batting, placed inside the Bladder of a Waterbed in order to absorb motion in the water as well as increase the Firmness of the bed. In general, more fiber filling results in greater Motion Separation and firmer Support.
Fill Level
A measurement of the depth of the Bladder in a Waterbed.
Filler
In mattress upholstery, refers to padding used underneath the mattress Cover to create its Quilted appearance. In a Latex mattress, refers to tiny particles of clay or other materials that are sometimes mixed into latex Foam, making the resulting latex less costly, but also stiffer and less Durable.
Firmness
The compression resistance of a mattress. Typically used in reference to a mattress' Support (particularly as provided by the Coils of an Innerspring Mattress), though sometimes also used to describe the softness or hardness of a mattress' surface (which relates more to its Comfort).
Flipping
The act of periodically turning over and/or rotating a mattress. Recommended to prevent Body Impressions.
Foam
Padding material used in mattresses as a supplement or alternative to an Innerspring Unit. Some common types used in mattresses include Latex, polyurethane and Memory Foam.
Foam Core
Slab of Foam that sits below the surface layer of a mattress, serving as the main support system. Sometimes known as a Molded Foam Core.
Foam Encasing
Stiff foam rails along the interior perimeter of a mattress, generally used to protect against Edge Break-Down. Also used in Air Beds and Soft-Sided Waterbeds to contain the Air Chamber or Bladder.
Foundation
Any base or support placed beneath a mattress. Term often used in reference to a Box Spring, but could also refer to a Torsion Module Foundation, Slatted Base or Platform Foundation. See our Foundation Guide to learn why foundations are important and how to evaluate different types of foundations.
Frame
Term that most commonly refers to a Bed Frame. In the case of a Hard-Sided Waterbed, refers to the rigid wood box that supports and contains the mattress, resting on top of the Deck and Pedestal. In the case of an Adjustable Bed, refers to the base unit that also provides the characteristic flexing motion.
Free Flow
Term that refers to a conventional Waterbed whose Bladder contains a single chamber with no Fiber Filling or other motion dampening attributes, such that the water is allowed to flow freely within the mattress.
Full
Mattress size that measures 54"W by 75"L. Also referred to as a double bed or a standard bed. Was the most common mattress size as recently as the 1970's.
Full Extra Long
Mattress size that measures 54"W by 80"L. Also referred to as double extra long.
Futon
Japanese-style Dual-Purpose Bed. A futon mattress consists of a Cover and filling material, which is typically Cotton but can contain an Innerspring Unit and/or Foam.
Gauge
A measurement of the thickness of the wire used in a Coil. The lower the gauge, the thicker/heavier the wire. Wire gauge for coils in an Innerspring Mattress generally falls between 12.5 and 17.0. See our Coil Guide to learn more about coil construction and what to look for in mattress coils.
Grid
The steel lattice surface that connects the top ends of the Coils in a Box Spring. Also known as a grid top.
Hard-Sided Waterbed
The classic Waterbed design, featuring an unstructured Bladder placed inside a special wood Foundation to hold the mattress in its proper shape.
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.
Hospital Bed
See Adjustable Bed.
Hybrid
Bed with a Core containing water or other liquid that otherwise resembles a traditional Innerspring Mattress in its Upholstery. Sometimes referred to as a Soft-Sided Waterbed.
Hydraulic Waterbed
Waterbed design wherein the Bladder is divided into numerous small compartments. Water is allowed to travel between the compartments in a controlled manner via small holes, enhancing both Support and Motion Separation.
IFD
See Indentation Force Deflection.
ILD
See Indentation Force Deflection.
Indentation Force Deflection (IFD)
A measurement of the Firmness of a given piece of Foam. 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 Load Deflection (ILD).
Inner Quilt
Found in a "true" Pillow-Top mattress, refers to the traditional layer of Quilting on top of which the separate pillow-top is sewn. Not all pillow-top mattresses actually have an inner quilt.
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 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.
Innerspring Unit
The spring and wire part of an Innerspring Mattress, comprised primarily of Coils, Helicals and Border Rods.
Insulation
Material used on top and bottom of an Innerspring Unit to prevent the Upholstery layers from settling down into the Coils. Common insulator materials include Fiber or Foam pads, non-woven fabric, netting or wire mesh. See our Upholstery Guide to learn more about the key elements of mattress upholstery and how they differ across mattresses.
Internal Load Deflection (ILD)
See Indentation Force Deflection.
King
Mattress size that measures 76"W by 80"L.
King Split
Bed that consists of two Twin Extra Long mattresses, each 39" wide x 80" long.
Knit
Fabric used in mattress Covers that is knitted rather than woven, creating a 'stretchier' and softer feel.
Latex
A spongy material produced from either natural or synthetic rubber. Used primarily in premium mattresses. See our Latex Mattress Guide for more information on the different types of latex mattresses and their various features and benefits.
Liner
See Safety Liner.
Loft
Term that describes the height and "fluffiness" of a material or padding.
Low-Profile Foundation
An extra-thin Foundation made to accompany an extra-thick mattress so that the total height of the bed will be more in keeping with a traditional sleeping surface.
Marshall Coil
See Pocketed Coil.
Mattress Handles
Fabric or cords sewn into the Upholstery of a mattress to aid in positioning it on the Foundation.
Memory Foam
A type of high-density polyurethane Foam known for its slow Recovery Time and its sensitivity to both weight and temperature, giving it a delayed Resiliency and allowing it to conform very closely to the shape of your body. Available in many depths and Densities, as well as different levels of Firmness. Also known as visco-elastic foam. See our Memory Foam Mattress Guide and Innerspring vs. Memory Foam sections for more information on memory foam mattresses and how they compare to Innerspring Mattresses.
Migration
Term that refers to the displacement of Fibers within a mattress over time. Can be mitigated with the use of certain higher-quality fibers and Quilt patterns.
Modules
See Torsion Bars.
Motion Separation
Refers to the degree to which movements on one side of the bed can be felt on the other side of the bed.
Mounting
The attachment of a Box Spring unit to a wood or metal Bed Frame.
Multi-Needle Quilting
Quilting process that uses multiple needles but features a continuous pattern. The tighter (closer together) the pattern, the firmer the feeling of the mattress surface. Also known as continuous quilting.
Natural Latex
Type of Latex produced from serum of the rubber tree. Known for its softness and Elasticity, as well as its biodegradability and inherent resistance to bacteria, mold and dust mites.
No-Flip Mattress
A mattress designed with a sleeping surface on only one side, such that it does not require end-over-end Flipping to provide continuous Support or to maintain its Warranty.
Offset Coil
Type of Innerspring Mattress Coil that has an hourglass shape similar to a Bonnell Coil, but with flattened edges at the top and the bottom of the coil to create better hinging action. Relative to Bonnell coils, Offset coils conform more to your body, make less noise, and are typically found in more expensive mattresses. See our Coil Guide to learn more about the various types of mattress coils and how to compare them.
Olympic Queen
Mattress size that measures 66"W by 80"L. Slightly wider than a standard Queen, which measures 60"W by 80"L.
Pedestal
A sturdy box that forms the base of a specially-designed Platform Foundation for a Hard-Sided Waterbed. Together with the Deck surface above, evenly distributes the weight of the mattress, so as to minimize strain on the Bladder seams as well as the floor.
Pillow-Top
A thick, soft, cushy layer of Foam, Cotton, wool and/or other Fibers that is attached loosely over the entire surface of the mattress.
Pincore Holes
Deep, cylindrical holes spread throughout a Latex mattress to help soften its feel. Larger pincore holes create a softer feel.
Platform Bed
Consists of a mattress placed directly on a Platform Foundation or other rigid platform.
Platform Foundation
Type of Foundation containing no load-absorbing metal components (such as Coils or Torsion Bars). Also known as a poly-box.
Plush
Term that refers to a softer level of surface Comfort.
Pocketed Coils
Type of Innerspring Mattress Coils that are individually wrapped in separate fabric pockets, providing more Motion Separation than other types of innerspring coils. Also known as Marshall coils. See our Coil Guide to learn more about the various types of mattress coils and how to compare them.
Pocketing
Refers to a form of mattress wear wherein layers of padding begin to settle into the Coils.
Poly-Box
See Platform Foundation.
Posturized
Refers to various types of additional support placed in the center of a mattress or Foundation to prevent Sagging.
Pressure Points
Specific places on the body where blood flow through the capillaries is restricted due to pressure from the sleeping surface against that area. Known to cause discomfort as well as tossing and turning.
Prorated Warranty
Mattress Warranty that does not cover the full mattress purchase price or replacement value after a certain period of time, requiring the customer to pay a portion of the original price to have it replaced, typically depending on how long the mattress was used.
Pure Latex
Term referring to Latex that does not include Fillers. Can be applied to either Synthetic or Natural latex. Most higher-quality latex mattresses use pure latex.
Queen
Mattress size that measures 60"W by 80"L. Currently the most common mattress size.
Queen Split
Bed that consists of two mattresses, each 30" wide x 80" long.
Quilting
The top-most layer of padding inside the mattress, consisting of Foam and/or Fibers stitched to the underside of the Ticking. Can provide additional Comfort, as well as a way for the mattress to breathe, and may also include a separate layer of padding such as a Pillow-Top or Euro-Top. Also refers to the process by which the quilting layer is stitched to the ticking and other padding layers of the mattress. Common quilting processes include Multi-Needle Quilting, Single-Needle Stitching, and Tack and Jump Quilting. See our Upholstery Guide to learn more about the key elements of mattress upholstery and how they differ across mattresses.
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.
Resiliency
Term used to describe the ability of an object or material (such as a Coil or padding layer) to spring back to its original form.
Sagging
Term referring to the loss of Support in a certain section of a mattress. Often confused with Body Impressions.
Safety Liner
Precautionary liner surrounding the Bladder of a Waterbed for containing water in the event of a leak or puncture.
Self-Inflating
Refers to a type of Portable Air Bed filled with sponge-like foam that self-expands as air is let into the mattress.
Semi-Fowler Position
A reclining position wherein the back rests at a 45-degree angle.
Semi-Waveless
Term used to describe a Waterbed whose Bladder contains a relatively small amount of Fiber Filling such that the motion of the water is reduced by roughly 50% relative to the motion in a Free Flow waterbed.
Set
Term referring to a mattress and a Foundation. Also referred to as a sleep set.
Single Bed
See Twin.
Single Extra Long
See Twin Extra Long.
Single-Needle Stitching
Quilting process more common in older mattresses wherein all Upholstery layers are stitched together with one long needle, resulting in a very hard mattress surface.
Slatted Base
Type of Foundation consisting of a wooden frame with slats going across the top, covered with fabric. Also referred to as a built-up foundation.
Sleep Set
See Set.
Soft-Sided Waterbed
Waterbed design featuring a Bladder surrounded by sturdy Foam Encasing and Upholstery, making its external appearance resemble that of a traditional Innerspring Mattress. Sometimes referred to as a Hybrid.
Smooth Top
Term used to describe a mattress cover that isn't Quilted.
Spring Mattress
See Innerspring Mattress.
Spring Wire
Refers to the strong, durable wires used to make the Coils in an Innerspring Mattress.
Stress Relief
See Tempering.
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
Term that refers to the aspects of the bed that push back in order to hold your spine in proper position while you sleep, so that you do not encounter pain and/or stiffness when you wake up. Can also encompass other attributes such as the degree to which the mattress conforms to your body. See our Support Guide to determine the best level of support for you.
Synthetic Latex
Type of Latex that shares many of the same physical properties as Natural Latex, but is made through a chemical process using petroleum-based materials. Generally considered slightly stiffer than natural latex, but also more consistent in quality, giving it slightly better Resiliency over a very long period of time.
Tack and Jump Quilting
Quilting process that uses hundreds of needles but is not limited to a continuous pattern, allowing for more Loft and a softer-feeling surface. Typically found in more expensive mattresses.
Talalay
Process in which liquid Latex is "whipped" with air until it becomes wet Foam, at which time it is poured into a mold, leaving room at the top. Once the mold is sealed, air is vacuumed out of the mold, causing the foam to expand such that it fills the empty space inside the mold. The mold is then frozen and quickly vulcanized, locking in the expanded structure of the foam. Tends to result in somewhat softer and less dense latex than the Dunlop process.
Tape Edge
The cord-like seam that runs along the edges of the mattress surface.
Tempering
Process by which Coils are treated to ensure that they return to their original shape and height after compression, improving their Durability and Resiliency. In the tempering process, coils are heated (or electrified) and then cooled, realigning the molecules in such a way that enhances the coil's strength and resistance to Sagging. Also referred to as stress relief. See our Coil Guide to learn more about coil construction and what to look for in mattress coils.
Ticking
Outer layer of fabric that encases the mattress and/or Foundation. Common types of ticking include Damask and Knit. Also referred to as the Cover. See our Upholstery Guide to learn more about the key elements of mattress upholstery and how they differ across mattresses.
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.
Torsion Module Foundation
Type of Foundation featuring Torsion Bars (rather than traditional Box Springs) to help absorb pressure placed on the mattress.
Tufting
The stitching that holds in place the padding layers of a mattress.
Twin
Mattress size that measures 39"W by 75"L. Sometimes referred to as a single bed.
Twin Extra Long
Mattress size that measures 39"W by 80"L. Sometimes referred to as single extra long.
Ultra-Waveless
Term used to describe a Waterbed whose Bladder contains a large amount of Fiber Filling such that the motion of the water is reduced by 95% or more relative to the motion in a Free Flow waterbed, allowing for virtually no movement of the water from one side of the bed to the other.
Upholstery
Refers to all soft layers in a mattress, including Insulation, Cushioning, Quilting and Ticking. Generally provides the mattress with its Comfort. See our Upholstery Guide for more about the various components of mattress upholstery and to learn how upholstery differs across mattress models.
Ventilator
Metal or plastic screens or eyelets placed in the sides of a mattress to allow air to pass through more easily.
Visco-Elastic Foam
See Memory Foam.
Wall-Hugger
Type of Adjustable Bed designed to maintain its alignment with bedside tables as its position is changed. Works by shifting the bed backward toward the wall as the head is elevated.
Warranty
A statement written by the manufacturer indicating the terms under which they will fix certain flaws in the design, materials and construction of a mattress. Generally does not offer protection against normal wear and tear or general deteriorations in Comfort. See our Warranty Guide to learn how warranties work and what to look for in a mattress warranty.
Waterbed
Type of bed distinguished by its use of liquid, rather than Coils, for Support. See our Waterbed Guide for more information on the different types of waterbeds and their various features and benefits.
Whisper Quiet
Term describing a motor or pump for an Adjustable Bed, Air Bed, or Waterbed that is encased in a special housing so as to dampen its sound.
Working Turn
A measurement of how tightly a Coil is wound. Each 360-degree revolution around the coil counts as two working turns. See our Coil Guide to learn more about coil construction and what to look for in mattress coils.
