What is your mattress actually made of?

Every mattress sold in a box looks the same from the outside: a rectangle in a fabric cover. What differs is the order and the thickness of what is inside, and that stack decides almost everything you will notice in year one and year seven. This is a plain-English tour of the layers and the words used to sell them.

As everywhere on this site, the descriptions below come from what manufacturers publish about their own construction. We do not cut mattresses open or run instrumented tests.

Three constructions, and what actually changes between them

Innerspring

A steel spring unit carrying the load, with a thin comfort layer on top. It is the oldest construction and still the most common one in physical stores. Air moves through a spring unit freely, so heat is rarely the complaint; the complaint is usually that you can feel your partner move, and that the thin top layer wears before the springs do.

All-foam

No steel at all: a firm foam base with softer foams above it. Foam absorbs movement instead of transmitting it, which is why a partner getting up at 6am is a non-event. The trade-off is heat — foam holds it — and edges, which are usually softer than a sprung mattress unless the maker has built a reinforced perimeter.

Hybrid

Pocket springs for the support core, foam on top for the feel. Each spring sits in its own fabric pocket and compresses more or less separately from its neighbours, which is what lets one side of the bed move without the other side following. Most of the mattresses sold online in Australia over about $700 are built this way.

	Innerspring	All-foam	Hybrid
Heat	Rarely an issue	The usual complaint	Between the two
Partner movement	Travels across	Absorbed	Mostly absorbed
Edge support	Usually firm	Softer unless reinforced	Usually firm
Weight	Heavy	Lightest	Heaviest
Boxed delivery	Rarely	Yes	Yes

The layers you are actually lying on

Almost every mattress, whatever the construction, is three jobs stacked up:

• The comfort layer (top 3–8 cm). This is what you feel in the first ten seconds and what sets the firmness label. It is also the layer that softens first.
• The transition layer. A slightly firmer foam that stops you sinking straight through the comfort layer into the hard part underneath. Cheap mattresses often skip it, and that is why they feel fine for a minute and wrong for an hour.
• The support core (the bottom half). Springs or high-density base foam. This is what holds your spine in line and what decides whether the mattress is still flat in seven years.

Foam words you will see on spec sheets

• Memory foam (viscoelastic). Softens with body heat and moulds slowly. Excellent at spreading pressure, slow to let you roll over, and the material most associated with sleeping warm.
• Polyurethane foam (polyfoam). The general-purpose foam used for transition and base layers. Responsive rather than slow. Density is what matters here, not the name.
• Latex. Springy and cool, made from rubber — natural, synthetic, or blended. Durable and expensive; one of the eleven we rank uses a latex layer — the Origin LumbarCloud — though it is a hybrid rather than an all-latex bed.
• Gel infusion, copper, graphite, phase-change covers. All aimed at the same problem, which is foam holding heat. They are real materials, but the size of the effect is not something a spec sheet can tell you.
• Density and ILD. Density predicts how long a foam lasts; ILD describes how firm it is. Brands rarely publish either, which is worth knowing when a page tells you a foam is “premium” and nothing else.

Proprietary names sit on top of all of this. Onebed’s Auralux and TEMPUR’s TEMPUR Material are the maker’s own names for their own formulations — useful for identifying a product, not for comparing one brand’s foam against another’s.

Springs: pockets, gauge and zones

In a pocket spring unit, three things get advertised. Count is how many springs sit under a standard size; more springs generally means finer contouring, though counts are quoted for different sizes and are not directly comparable. Gauge is the wire thickness: thicker wire is firmer and usually more durable. Zones means the unit is divided along its length, with firmer springs under the hips and softer ones under the shoulders.

Zoning is the one that shows up most in Australian marketing. It is a real construction feature and it is worth having, but the number of zones is not a score — a well-built five-zone unit will beat a poorly-built seven-zone one.

Covers, and why they matter more than you would think

The cover is the only part of the mattress your skin actually meets, and it is the part most likely to decide whether you feel warm. Look for two things: whether it is removable and washable, and whether the fabric is knitted (stretchy, follows the foam) or woven (firmer, holds its shape). A removable cover also makes a spill survivable, which matters because stains are the most common reason a warranty claim is refused.

Where the eleven we rank sit

Of the eleven mattresses on this site, six are hybrids — the Newentor Hybrid, the Newentor Hybrid Pro, the Origin Hybrid Pro, the Origin LumbarCloud, the Emma Luxe ViscoCool and the Sleeping Duck Mach II. Four are all-foam: Onebed, Koala, Ecosa and the TEMPUR Ease 20. One, the Sealy Posturepedic Exquisite Rosewood, is a traditional innerspring. Every construction and material we have on record is listed on each mattress’s own page and in the side-by-side comparison.

The short version

• The support core decides how long it lasts. The comfort layer decides how it feels on night one.
• Foam absorbs movement and holds heat. Springs move air and transmit movement. Hybrids split the difference.
• Zone counts, spring counts and foam brand names are not scores. Density, gauge and layer thickness are the real specifications, and they are the ones least often published.
• A removable, washable cover is worth more than most of the words on the spec sheet.