Mattress Glossary: 60 Sleep and Mattress Terms Explained (South Africa)

This glossary explains 60 mattress and sleep terms in plain South African English, from foam density and pocket springs to queen bed dimensions and warranty small print. Every definition is 40 to 60 words, and every Mr Mattress figure quoted here comes from our own published specs and live prices, checked on 19 July 2026.

Mattress shopping has its own vocabulary, and half the frustration of comparing beds is that brands use these words loosely. This page pins each term down. The definitions are alphabetical, so you can scroll to the word you need, and where a term touches a Mr Mattress range we quote the real published figures rather than rounded marketing numbers. For the full technical table behind those figures, see the range specs page; for how firmness terms fit together in practice, see the firmness guide.

The terms, A to Z

Active Foam

Active Foam is a firm Mr Mattress range built on a 50 kg/m3 chip foam core with a 27 kg/m3 pure virgin foam comfort layer. It stands 200 mm tall, is rated for sleepers up to 100 kg, carries a 10 year warranty and starts at R3,399.

Back sleeper

A back sleeper rests face up with weight spread evenly along the spine. This position generally needs a medium-firm to firm surface that supports the lumbar curve without letting the hips sink below the shoulders. Firmer ranges such as Comfort Foam, Active Foam and the Hybrid suit most back sleepers.

Base set

A base set is a mattress sold together with its matching bed base, usually at a lower combined price than buying the two pieces separately. Mr Mattress lists base set options on every mattress range, and a solid base also protects the mattress by giving it even, stable support.

Bed base

A bed base is the platform a mattress stands on, replacing or sitting inside a bed frame. Common South African types include sleeper bases and drawer bases with built-in storage. A flat, sturdy base helps the mattress wear evenly, while a sagging base or widely spaced slats shorten its life.

Body impression

A body impression is a shallow, permanent dip that forms where a sleeper lies night after night as comfort foams settle. Light impressions are normal in any mattress. Deep impressions that pull the spine out of line signal worn materials, which is why warranties usually specify a maximum impression depth.

Bonnell spring

A Bonnell spring is an hourglass-shaped steel coil, laced to its neighbours in a connected unit, and one of the oldest proven support systems in mattress making. Bonnell units are durable, breathable and evenly supportive, though connected coils transfer more movement across the bed than individually wrapped pocket springs.

Breathability

Breathability describes how easily air moves through a mattress, carrying body heat and moisture away from the sleeper. Open spring designs breathe well, while dense foams hold more warmth. Quilted covers, gel infusions and ventilated layers all improve airflow, which matters in warm South African summers, especially for hot sleepers.

Chip foam

Chip foam, also called rebonded foam, is made by bonding shredded high-density foam pieces into a single dense block. The result is heavier, firmer and more resistant to body impressions than standard foam of the same feel. Mr Mattress uses chip foam cores of 45 to 65 kg/m3 across its foam ranges.

Combination sleeper

A combination sleeper changes position through the night, moving between side, back and stomach rather than settling into one posture. Medium-firm surfaces suit this style best because they handle every position acceptably. A responsive surface that makes turning over easy matters more here than deep, slow-moving contouring.

Comfort Foam

Comfort Foam is the entry-level Mr Mattress range, built on a 45 kg/m3 high-density chip foam core that resists body impressions. It is a firm mattress, 160 mm tall, rated for sleepers up to 80 kg, and it carries a 3 year written warranty with prices from R2,399.

Comfort layer

The comfort layer is the top section of a mattress, the part your body actually feels. It cushions shoulders and hips and determines the surface feel, from plush to firm. Typical materials include memory foam, virgin foam and latex. Beneath it, the support core does the structural work.

Comfort trial

A comfort trial is a period after delivery during which you can sleep on a mattress at home and still return or exchange it. Mr Mattress offers a 365 night comfort trial on every mattress, letting you judge the bed through summer and winter before the decision becomes final.

Contouring

Contouring is how closely a mattress surface moulds to the shape of your body, filling the curves at the waist and lower back while letting shoulders and hips settle in. Memory foam, like the top layer of the Revive range, contours strongly; firmer virgin foams contour less and feel springier.

Density (foam density)

Foam density measures the weight of foam per cubic metre, written as kg/m3. It is the best single predictor of durability, because higher density foam resists sagging and body impressions for longer. Mr Mattress publishes its core densities openly, from 45 kg/m3 on Comfort Foam to 65 kg/m3 on Revive.

Double bed

A double bed in South Africa measures 137 cm wide by 188 cm long. It sleeps one adult in comfort or two adults snugly, with each partner getting less width than a single bed offers. Doubles remain popular for guest rooms, teenagers and couples working with smaller bedrooms.

Edge support

Edge support is a mattress's ability to stay firm at its perimeter, so you can sit on the side or sleep near the edge without rolling off or feeling the border collapse. Reinforced edges and dense cores improve it, effectively enlarging the usable sleep surface, which matters most on shared beds.

Extra length (XL)

Extra length, or XL, is a South African sizing option that stretches a mattress from the standard 188 cm to around 200 cm long, while the width stays the same. It suits sleepers taller than about 1.85 m, whose feet would otherwise hang over the end of a standard bed.

Firm mattress

A firm mattress offers minimal sink and a stable, well supported surface, suiting back sleepers, stomach sleepers and heavier bodies. Firmness describes support rather than hardness, so a firm bed can still have a cushioned surface feel. The Comfort Foam, Active Foam and Hybrid ranges are all rated firm.

Firmness scale

The firmness scale rates mattress feel from 1, the softest, to 10, the firmest, usually grouped into soft, medium, medium-firm, firm and extra-firm bands. No official standard governs the numbers, so brands calibrate differently. Judge a mattress by how level it keeps your spine, not by the label alone.

Foam mattress (full foam)

A full foam mattress uses layered foams for both support and comfort, with no springs anywhere in the build. A dense core provides the structure while softer upper layers shape the feel. Benefits include quiet sleep, excellent motion isolation and no coils that can eventually wear, squeak or poke through.

Gel-infused foam

Gel-infused foam is memory or comfort foam blended with gel particles or beads that absorb and spread body heat. The goal is a cooler surface feel than traditional memory foam, which can retain warmth. Infusions help most during the first part of the night, in warm rooms and warm climates.

Guarantee

A guarantee is a seller's broad promise, often covering satisfaction, while a warranty is a written commitment to repair or replace a product with a defined defect over a stated period. In South Africa the Consumer Protection Act adds baseline rights on defective goods regardless of what any brand promises.

High-density foam

High-density foam contains more material per cubic metre than standard foam, making it heavier, more supportive and far more resistant to sagging. Mr Mattress cores range from 45 kg/m3 in the Comfort Foam to 65 kg/m3 in the Revive. Density is durability: denser cores keep their shape for longer.

Hybrid mattress

A hybrid mattress combines two support technologies in one bed: a steel spring core underneath for responsive support, and a substantial foam comfort layer on top for pressure relief. The design keeps the familiar springy feel while replacing the thin padding that made older spring beds uncomfortable over time.

Hybrid range (Mr Mattress)

The Hybrid is the Mr Mattress range that pairs a spring support core with a thick foam comfort layer, a transition layer and full edge support. It carries a firm rating, is available in double, queen and king options, comes with a 10 year warranty and starts at R4,999.

Hypoallergenic

Hypoallergenic describes materials unlikely to trigger allergies. Dense foam mattresses are naturally resistant to dust mites, which need looser, airier padding to colonise, making foam a sensible choice for allergy-prone sleepers. Pairing the mattress with a washable protector and airing the bedroom regularly keeps allergens down further.

Indentation

An indentation is a visible hollow left in the sleep surface after materials compress permanently, deeper and more localised than normal settling. Warranties distinguish normal impressions from defects by depth, so measure with a straight edge laid across the bed. Rotating the mattress regularly spreads the load and slows indentation.

King size bed

A king size bed in South Africa measures 183 cm wide by 188 cm long, the widest standard local size. It gives each partner about 91 cm of personal space, roughly a single bed each, making it the most comfortable option for couples, restless sleepers and families with visiting children.

Latex

Latex is a springy, durable mattress material made from rubber tree sap, synthetic rubber or a blend of the two. It offers responsive contouring, sleeps cooler than traditional memory foam and resists dust mites naturally. Its main drawbacks are weight and price, with natural latex among the most expensive materials.

Mattress lifespan

Mattress lifespan is how long a bed keeps supporting your spine properly, typically seven to ten years for quality foam builds. Core density is the biggest factor, followed by sleeper weight and care. Sagging, deep impressions and waking up sore on a bed that once felt fine signal the end.

Mattress protector

A mattress protector is a thin, washable layer, usually waterproof, that shields the mattress from spills, sweat and dust. It is the cheapest way to extend mattress life, and it keeps the bed hygienic in case a warranty assessment or trial return is ever needed. Choose a breathable design.

Mattress rotation

Mattress rotation means turning the bed 180 degrees so the head end becomes the foot end, moving your heaviest contact points onto fresher material. Rotate a new mattress every month or two for the first six months, then quarterly. Single-sided mattresses should be rotated, never flipped over.

Medium-firm

Medium-firm sits in the 5 to 7 band of the firmness scale and is the most popular feel worldwide, with around 80 percent of sleepers settling here. It balances pressure relief with spinal support across most body types and positions, making it the safest starting point for shared beds.

Memory foam

Memory foam is a slow-responding polyurethane foam that softens with body heat and moulds to your shape, then recovers when you move. It excels at pressure relief and motion isolation. The Mr Mattress Revive range uses a 30 kg/m3 pure memory foam top over a high-density chip foam core.

Motion isolation

Motion isolation is a mattress's ability to absorb movement where it happens instead of transmitting it across the bed, so one partner turning over does not wake the other. Foam mattresses, especially memory foam designs, isolate motion best, which makes them a strong choice for couples and light sleepers.

Motion transfer

Motion transfer is the ripple of movement that travels across a mattress when a sleeper moves, the opposite of motion isolation. Connected spring systems transfer the most motion because the coils are laced together, while dense foam layers and individually wrapped springs absorb movement before it reaches your partner.

Off-gassing

Off-gassing is the faint, new-mattress smell released by fresh foams as manufacturing gases disperse. It is temporary and harmless for most people, typically fading within a few days to two weeks. Unwrap a new mattress in a ventilated room and let it air before dressing it with bedding.

Orthopedic mattress

Orthopedic mattress is a marketing description, not a regulated standard, and no authority certifies a bed as orthopedic. The term signals a design aimed at firm, even spinal support. Rather than trusting the label, check the measurable things: core density, firmness rating, weight capacity and the length of the warranty.

Pillow top

A pillow top is an extra cushioning layer sewn onto the mattress surface as a separate, visible pad, giving a plusher first-touch feel. Because pillow tops compress before the layers beneath them, low-density versions can hollow early. A quilted top achieves a softer surface with the padding stitched in integrally.

Pocket spring

A pocket spring is a steel coil sewn into its own fabric sleeve so it compresses independently of its neighbours. A pocket spring unit contours more precisely and transfers less motion than connected coil systems, which is why it features widely in premium spring and hybrid mattresses across South Africa.

Polyurethane foam

Polyurethane foam, or PU foam, is the workhorse material of modern mattress making, produced in an enormous range of densities and feels. Chip foam cores, virgin foam comfort layers and memory foam are all polyurethane variants. Density, not the name on the label, determines how well each one lasts.

Pressure point

A pressure point is a spot where body weight concentrates against the mattress, typically the shoulders, hips and knees, restricting circulation and causing tossing, turning and numbness. Contouring comfort layers spread that concentrated load across a wider area, which is why side sleepers notice pressure relief the most dramatically.

Pressure relief

Pressure relief is a mattress's ability to spread body weight so that no single point carries too much load. It comes from comfort layers that compress and contour, like memory foam, letting shoulders and hips sink slightly while everything else stays supported. Good pressure relief means less tossing and turning.

Queen size bed

A queen size bed in South Africa measures 152 cm wide by 188 cm long and is the country's most popular size for couples. It gives each partner 76 cm of width, a comfortable step up from a double, while still fitting most main bedrooms with room to walk around.

Quilted top

A quilted top is a mattress surface where soft padding is stitched directly into the cover in a decorative pattern, giving a gently cushioned first touch without a separate pillow top pad. Quilting adds surface softness and breathability while keeping the sleeping surface smooth, durable and less prone to hollowing.

Revive Foam

Revive is the Mr Mattress memory foam range: a 65 kg/m3 high-density chip foam core under a 30 kg/m3 pure memory foam top that contours to shoulders and hips. It has a medium rating, stands 240 mm tall, is rated to 140 kg, carries a 10 year warranty and starts at R4,899.

Sagging

Sagging is a structural dip in a mattress, usually across the middle third where the hips rest, that no longer springs back. Unlike surface impressions, sagging means the support core itself has broken down and the spine can no longer stay level. It is the clearest sign a mattress needs replacing.

Sciatica

Sciatica is nerve pain that runs from the lower back down the leg along the sciatic nerve. A mattress cannot treat sciatica, but a supportive medium-firm to firm surface that keeps the spine and pelvis aligned can reduce overnight aggravation. Persistent symptoms belong with a healthcare professional, not a mattress label.

Side sleeper

A side sleeper rests on one shoulder and hip, concentrating weight on the body's two widest points. This position needs a medium to medium-firm surface with enough give for those points to settle in while the waist stays supported. Contouring tops, like the Revive range's memory foam, suit side sleepers.

Single bed

A single bed in South Africa measures roughly 91 to 92 cm wide by 188 cm long, the standard size for one child, teenager or adult sleeping alone. It fits small bedrooms easily and is the usual choice for bunk beds, guest rooms and first beds after a cot.

Spinal alignment

Spinal alignment means your spine holds its natural, gentle curves while you sleep, without sagging into the mattress or arching away from it. Whatever your sleeping position, your ears, shoulders and hips should form a straight line. It is the single most useful test of whether a mattress suits you.

Stomach sleeper

A stomach sleeper lies face down, the position that puts the most strain on the lower back, because the abdomen sinks while the neck twists sideways. Stomach sleepers need a firm surface that keeps the pelvis level with the shoulders, and a low pillow, to keep the spine as straight as possible.

Support core

The support core is the deep, dense base layer of a mattress that does the structural work: holding your spine level under full body weight, night after night, for years. In foam mattresses the core is high-density foam; in spring and hybrid designs it is the steel coil unit.

Three-quarter bed

A three-quarter bed is a distinctly South African size measuring 107 cm wide by 188 cm long, sitting between a single and a double. It suits growing teenagers and single adults who want more room than a single bed in a compact bedroom. Mr Mattress offers three-quarter options across its foam ranges.

Transition layer

A transition layer sits between the soft comfort layer and the firm support core, bridging the two so your body settles gradually instead of hitting an abrupt change in feel. It also protects the comfort layer from bottoming out. The Mr Mattress Hybrid includes a transition layer in its build.

Turnable mattress

A turnable, or double-sided, mattress has identical comfort layers on both faces so it can be flipped to share wear between two surfaces. Most modern mattresses, including every current Mr Mattress range, are single-sided layered designs that are rotated head to toe instead, a trade-off covered in our turnable mattress guide.

Virgin foam

Virgin foam is new, first-run polyurethane foam made directly from raw materials, as opposed to rebonded chip foam made from bonded offcuts. It gives a consistent, resilient comfort feel. The Active Foam range pairs a 27 kg/m3 pure virgin foam comfort layer with its dense chip foam support core.

Warranty

A warranty is the manufacturer's written commitment to repair or replace a mattress with a genuine defect, such as excessive sagging, within a stated period. Mr Mattress warranties are tiered: 3 years on Comfort Foam and 10 years on Active, Revive and Hybrid. Warranties cover defects, not normal gradual softening.

Weight rating

A weight rating states the sleeper weight a mattress is engineered to support without premature breakdown, and exceeding it accelerates sagging. Mr Mattress publishes its ratings openly: 80 kg on Comfort Foam, 100 kg on Active and 140 kg on Revive, so heavier sleepers can choose a core built for them.

Zoned support

Zoned support divides a mattress into areas of different firmness, firmer under the hips where weight concentrates and softer under the shoulders where a little sink is welcome. The aim is straighter spinal alignment for a wider range of bodies. Zoning appears mostly in premium builds and helps side sleepers most.

Keep reading

Now that the vocabulary is settled, these guides put it to work: the mattress firmness guide for matching feel to your body and sleep position, the hybrid mattress guide for how spring and foam work together, the turnable mattress guide for the full single-sided versus double-sided story, the back pain buying guide for support-first shopping, and the beds for sale hub for current prices. Or browse the full range directly.

About Mr Mattress

Mr Mattress manufactures foam and hybrid mattresses in South Africa through our own and approved partner facilities in Gauteng, Cape Town and East London, with our head office and main factory in Bloemfontein. Every mattress comes with a 365 night home trial and a written warranty: 3 years on Comfort Foam, 10 years on Active, Revive and Hybrid. Delivery is free. Free State customers: usually 1 to 3 working days; national orders: 3 to 7 working days depending on your area. Visit one of our stores across South Africa, with more opening, or call us on 087 087 1610.

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