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Mattress specification glossary

Mattress Specification Glossary

Plain-English definitions of the terms you'll meet on mattress labels and in our reviews.

Published byWantMattress editorial team

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A

Adjustable Base Friendly Mattress

A mattress manufactured to be used with an adjustable base.

Air Chambers

Air-filled support components used in adjustable air mattresses, allowing the firmness to be changed by adding or removing air.

Air Mattress

A bed filled with air. It provides varied firmness levels by adjusting air pressure, perfect for temporary sleeping arrangements.

Aloe Vera

A natural extract sometimes infused in mattress covers or foam to promote a soothing, antimicrobial surface and help maintain freshness.

Antimicrobial

A feature in some mattress and bedding materials that prevent the growth of bacteria and fungi. It contributes to a cleaner sleeping environment.

Anti-Allergy Cover

A mattress cover designed or treated to reduce common allergens like dust mites; often synonymous with a hypoallergenic cover. See our range of anti-allergy mattresses.

B

Bamboo Fabric

A sustainable fabric derived from bamboo plants. It’s hypoallergenic, breathable, and possesses natural moisture-wicking properties, promoting a cool sleep environment.

Base Foam

The foundational layer in many mattresses, offering structural support and durability.

Bio Foam

A type of polyurethane foam partially made from plant-based materials (such as soy) to reduce reliance on petrochemicals while maintaining comfort and support.

Body Indents

Impressions that form over time on the mattress surface due to consistent sleeping positions. Like your shoes forms your footprint, this means the mattress has adapted to you.

Breathability

The mattress’s ability to circulate air and prevent overheating. Essential for a cool and comfortable sleep.

Bonnell Coil

The oldest coil type used in innerspring mattresses. It’s hourglass-shaped and offers a durable yet bouncy feel.

C

Celliant Fabric

A high-tech fabric that converts body heat into infrared energy. It can promote better oxygen levels and more restful sleep.

CertiPUR-US Certified

A certification ensuring the foam used in mattresses is free from harmful chemicals and has low VOC emissions. It also promotes better indoor air quality.

Certified Organic

Materials grown and processed without synthetic chemicals or pesticides, adhering to strict organic standards. It offers a cleaner sleep environment.

Charcoal-Infused Foam

Foam that has been blended with activated charcoal (often from bamboo) to help neutralize odors and absorb moisture, contributing to a fresher mattress.

Coil / Spring

Metal springs in innerspring mattresses. They’re key for support in an innerspring mattress.

Coil Count

Indicates the number of springs in a mattress; higher counts often suggest better support.

Coil Gauge

Refers to the thickness of the mattress coils. A lower number means thicker coils, often translating to a firmer feel.

Coil-on-Coil

A mattress design featuring two layers of springs stacked on each other. Typically, a layer of smaller or softer coils sits above a layer of larger or firmer coils, enhancing support, durability, and luxury feel.

Comfort Layer

The topmost layer, designed for maximum sleep comfort and pressure relief.

Continuous Coil

A system where the coils are interconnected in one continuous piece, an enhancement in durability and support from the original Bonnell Coil.

Convoluted Foam (Egg Crate Foam)

Foam cut with peaks and valleys (resembling an egg crate) to improve airflow and cushioning. Often used in mattress toppers or as a comfort layer for additional pressure relief.

Copper-Infused Foam

Foam (usually memory foam) that has tiny copper particles or strands added. The copper can help draw away heat and may provide antimicrobial benefits for a cooler, cleaner sleep surface.

Coir

A coarse fiber from coconut husks, used in some mattresses as a firm, breathable layer (often in natural or crib mattresses) to provide support and airflow.

Cover (Ticking)

The outer fabric that encases the mattress. It holds all the layers together and is sometimes crafted with special materials (cooling fabrics, organic cotton, etc.) for added comfort and protection.

D

Damask

A durable woven fabric often used as a traditional mattress cover (ticking). Damask covers are known for their sturdy feel and patterned designs, offering a classic look and long-lasting wear.

Dunlop Latex

A natural latex process that results in denser, more supportive foam. It’s less bouncy than Talalay latex.

Dust Mites

Very small insect-like pests that can populate mattresses, feeding on dead skin cells and causing allergies. Regular cleaning and a mattress protector help reduce their numbers.

E

Edge Support

Defines how well a mattress supports weight at its edges. A well-supported edge makes the mattress feel larger by reducing any roll-off sensations near the edges.

Egyptian Cotton

A luxurious, soft cotton known for its longer fibers and superior strength. It’s often used in premium bedding and mattress covers.

Euro Top

Similar to a pillow top. However, its padding is stitched flush with the mattress for a plush feel without adding too much additional height to the mattress.

Extra Firm

A mattress with very minimal give. This firmness is ideal for certain back and stomach sleepers.

F

Fiberglass

A material composed of tiny glass fibers, often used in mattress fire barriers for its flame-resistant properties. It should remain contained within the mattress cover, as direct contact can irritate skin or lungs.

Fire Barrier

Any flame-retardant layer or treatment in a mattress designed to slow or prevent the spread of fire. It can be made from fiberglass, Kevlar, wool, or treated fabrics to meet safety standards.

Fire Sock

A specific type of fire barrier: a sock-like tube of fire-resistant material that fully encases the mattress's foam or inner materials. In the event of a fire, it melts or chars to help smother flames.

Flippable Mattress (Double-Sided)

A mattress designed to be used on both sides. It has sleeping surfaces on the top and bottom, allowing it to be flipped over periodically to distribute wear and extend its lifespan.

Foam Density

Refers to the compactness of the foam. Higher density will provide a firmer feel, while a lower density will provide a softer one.

Foam Encasement

A firm foam border surrounding the perimeter of an innerspring or hybrid mattress. It reinforces the edges to provide better edge support and a consistent feel across the mattress.

Firmness

An indicator of how hard or soft a mattress feels. It’s a critical aspect of mattress comfort and comes in various levels, like soft, medium, and firm.

G

Gel-Infused Foam Mattress

Foam infused with gel; this technology strengthens the foam for longer lasting comfort and distributes body heat, ensuring cooler sleep. Browse our cooling gel mattress options.

Gel-Infused Memory Foam

Memory foam combined with gel particles. The infusion promotes cooling and combats the heat retention issues common in traditional memory foam, a feature of many gel mattresses.

Graphite-Infused Foam

Foam (often memory foam) that has graphite particles infused to conduct heat away from the body. This helps dissipate warmth and keep the mattress cooler during sleep.

Green Tea Foam

Memory foam that is infused with green tea extract (and sometimes charcoal) to reduce odor and bacteria. Often found in mattresses that emphasize a fresher, more natural foam product.

H

Handles

Sturdy fabric loops sewn onto the sides of some mattresses. They make it easier to maneuver, rotate, or flip the mattress as needed for maintenance.

High-Density Foam (HD Foam)

Foam with a higher mass per unit volume, making it firmer and more durable. High-density foam is often used in support cores to increase a mattress’s longevity and support.

High-Resilience Foam (HR Foam)

A premium grade of polyurethane foam known for its bounciness, quick rebound, and durability. It provides strong support while still contouring somewhat, and is often used in higher-quality foam and hybrid mattresses.

Hybrid

A blend of different technologies including: innerspring coils, latex, and/or foam layers, as used across our hybrid mattress collection. This bed provides a balance of support from coils with foam for comfort.

Hypoallergenic (Allergens)

Materials that help reduce allergic reactions. It’s essential for those sensitive to common allergens like dust mites or pollen. Explore our allergy-friendly mattress options.

I

Indentation Load Deflection (ILD)

A measurement of foam firmness. ILD is determined by how much force is required to compress a foam sample by 25% of its height. A higher ILD number indicates a firmer foam, while a lower number indicates a softer foam.

Innerspring

A classic mattress type, primarily made of coil springs, like those in our traditional spring mattresses.

L

Latex

A bed made from natural or synthetic rubber. Known for its durability, our latex mattresses offer a unique balance of support and comfort.

Lumbar Support

Extra reinforcement or support targeted at the lower back area of a mattress. Mattresses with a dedicated lumbar support feature will be firmer or more supportive in the middle section to help maintain the natural curve of your lower spine, which can be beneficial for back sleepers or those with lower back pain.

M

Medium

A balanced level of firmness, offering support and cushioning.

Medium Soft

A slightly plush feel with underlying support, our soft-medium firmness. It’s a midway between soft and medium.

Memory Foam (Viscoelastic Foam)

A popular mattress material that conforms closely to the body, found across our memory foam mattress range. It offers pressure relief and motion isolation.

Microcoils

Very small, thin coils (usually 1–3 inches tall) used in some mattresses’ comfort layers. Microcoils add a layer of adaptive support, improve airflow, and can increase the mattress’s responsiveness and durability.

Moisture Wicking

Materials designed to draw moisture away from the body, ensuring a dry and comfortable sleep environment.

Motion Isolation

A mattress’s ability to prevent movement from one side from disturbing the other side. This feature is ideal for couples with different sleep schedules.

Plush

A soft and luxurious feel, often added via pillow tops or plush comfort layers.

N

Nanocoils

Extremely small coils (often less than 1 inch tall) that function similarly to microcoils but on an even smaller scale. They provide a thin layer of flexible support and can enhance airflow and precision in cushioning.

Natural Latex

Latex foam made primarily from rubber tree sap (usually at least 95% natural latex). It is springy, durable, and derived from a renewable resource, a hallmark of our natural mattress selection, without the use of harsh chemicals in its creation.

No-Flip Mattress (No-Turn)

A mattress built with one sleep surface. These one-sided mattresses should not be flipped; maintenance involves rotating the mattress end-to-end rather than turning it over.

O

OEKO-TEX Standard

A certification indicating the absence of harmful substances in textiles. It ensures safety for direct skin contact.

Octaspring

A patented mattress technology featuring foam springs in a honeycomb, eight-sided tube design. These foam spring layers aim to combine the support of springs with the comfort of foam, enhancing airflow and targeted support (used by the Dormeo brand).

Off-Gassing

Refers to releasing a distinct chemical smell after unboxing a new mattress. Typically, it dissipates after a few days of airing out.

Open Coil

A term referring to traditional innerspring mattresses that use interconnected hourglass-shaped springs (such as Bonnell coils) in a linked network. Open coil mattresses are common, generally affordable, and provide a bouncy, firmer feel, though they can transfer motion more than pocketed coils.

Orthopedic Mattress

A non-medical term used for mattresses that are extra firm or specially designed to support the back and joints. It implies a mattress that promotes proper spinal alignment and relieves pressure points, often marketed to people with back pain. Compare our orthopaedic mattresses.

Organic

Mattresses or materials sourced without synthetic fertilizers, pesticides, or genetically modified organisms. Often preferred for eco-friendliness and health concerns.

Organic Latex

Latex derived from rubber trees without synthetic additives, featured among our natural and organic mattresses. It’s eco-friendly and hypoallergenic.

Outlast

A phase-change fabric technology originally developed for NASA, used in some mattress covers. Outlast materials absorb, store, and release body heat to regulate temperature, helping prevent overheating during the night.

Offset Coil

To increase coil count and support, an Offset coil design nestles the coils together like a "honeycomb" shape, instead of lining them side by side.

P

Phase Change Material (PCM)

Substances used in some mattress foams and fabrics that actively absorb and release heat as they change phase (from solid to liquid and vice versa). PCM helps regulate temperature by pulling heat away when you’re too warm and releasing it back if you start to cool down, maintaining a more constant comfort level.

Pillow Top

An extra layer stitched on the mattress surface. Especially great for side sleepers, it provides an added cushion able to hug your hips and shoulders for optimal pressure relief.

Plush

A soft and luxurious feel, often added via pillow tops or plush comfort layers.

Pocketed Coil

Individually wrapped coils that move independently, the defining feature of a pocket spring mattress. They offer targeted support and motion isolation.

Polyfoam (Polyurethane Foam)

A common type of foam used in mattresses, made from polyurethane. Polyfoam comes in various densities and qualities; higher-density versions are often used in support layers, while softer, lower-density polyfoams may appear in comfort layers.

Posturepedic

A trademarked term (by Sealy) referring to a design that provides enhanced support in the center third of the mattress, where your body weight is concentrated. Often used broadly to suggest posture-supporting orthopaedic designs in a mattress.

Purotex

A probiotic textile treatment applied to some mattress covers. Purotex releases friendly probiotics that help reduce allergens (like dust mite debris) and bacteria, aiming to create a cleaner, healthier sleeping environment.

Pressure Relief

A mattress’s capability to alleviate tension from pressure points like hips, shoulders, and knees, which is important for side sleepers.

Q

Quilting

The top layer of a mattress that provides a cushiony feel. It also protects the underlying layers.

R

RV Mattress

Specifically designed for campers or recreational vehicles. It’s often more compact but still offers comfort for on-the-road sleeping.

Reflex Foam

A firm, high-density polyurethane foam often used as a supportive core in mattresses. Reflex foam has minimal give (hence "reflex"), providing solid, orthopedic-level support, and is commonly found in all-foam mattresses or as a base under softer layers.

Resilience

The speed at which a mattress regains shape after pressure. High resilience means quick bounce-back.

Responsiveness

How quickly a mattress material reacts to changes in pressure or movement. A responsive mattress adjusts rapidly when you move or change positions, while a less responsive one (like some memory foams) takes longer to regain its shape.

S

Soft

Mattresses that offer a cushioning effect, enveloping the sleeper for a cloud-like experience.

Support Layer

This section offers support below the comfort layer, ensuring proper spinal alignment through the night.

Synthetic Latex

Latex foam produced from petrochemicals (styrene-butadiene rubber) rather than natural tree sap. Synthetic latex tends to feel similar to natural latex but is usually less expensive and slightly less durable.

T

Talalay Latex

A latex processing method that produces a lighter, consistent, and more buoyant feel than Dunlop latex.

Temperature Regulation

A mattress’s ability to maintain a neutral temperature. This feature ensures neither too hot nor too cold sleeping conditions, valued by hot sleepers.

Tempur

A brand-name memory foam originally developed from NASA technology. "Tempur" foam (used by Tempur-Pedic) is known for its high density and excellent pressure relief. The term is often used to imply premium, slow-response memory foam.

Transition Layer

A layer in a mattress that sits between the softer top comfort layers and the firm base layer. The transition layer helps gradually increase firmness to prevent a too-sharp change from soft to hard, enhancing comfort and support as you lie deeper into the mattress.

Trial Period

The time frame during which you can try out a new mattress at home and return or exchange it if it doesn’t meet your needs. Trial periods are a common offering, especially for online mattress brands.

W

Waterbed

A bed filled with water. It provides a unique sensation, known for its therapeutic benefits and gentle support.

X

X-Firm

An abbreviation for "extra firm," used to describe a mattress feel that is very hard with minimal cushioning. An X-Firm mattress offers the highest level of firmness, providing very strong support with little sinkage.

Y

YKK Zipper

A high-quality, durable zipper made by the YKK company, often used in removable mattress covers. If a mattress mentions a YKK zipper, it implies the cover is built with a reliable zipper that is less likely to snag or break.

Z

Zip and Link

A configuration mostly found in UK bedding: two mattresses that can be zipped together along the side to form one large mattress (often a king or super-king size). This allows partners with different comfort preferences to have separate mattresses, or for easy transport and flexibility in guest rooms.

Zoned Support

A mattress design feature where different sections (zones) of the mattress have varying firmness levels or support types. For example, a common 3-zone design might have a firmer middle for the hips and lower back and softer zones at the shoulders and legs, promoting better spinal alignment.