What Are Mattresses Made Of?

Young smiling couple in furniture store showroom

As a child, I often had difficulty falling asleep. My brain would go on all sorts of tangents, including (but far from limited to) how common household objects such as taps were constructed, and therefore how they worked. Alas this nocturnal curiosity never really did amount to anything in my daily life. When Youtube got big, I spent my time watching videos of puppies rather than answering all my childhood questions. 

One object I often wondered about was the bed I lay on. I knew I wouldn’t like my parents’ reaction though if I’d gone and cut my mattress open, and so my curiosity stayed unsatisfied then faded. As an adult looking to buy a new bed though, that curiosity returned. It makes sense to want to understand what you’re buying, particularly if you’re going to put a solid chunk of money down for it. And in order to understand what you’re buying and how it works, in order to understand what you personally will want to look for in a mattress, you need to understand what mattresses are made of. 

In the types of mattresses article, I briefly outlined the two main parts of a mattress, and then also briefly introduced each type of mattress. This article will go more in depth into the two sections, and explore how the various materials available for each section will affect your sleep. 

Two Sections of a Mattress

A mattress can be divided into its two main components –the upholstery, or comfort layer, and the core, or support layer. As you can tell by their second names, the layers are there to provide comfort and support respectively. 

The goal of a mattress is to keep your spine straight as you sleep, and distribute your weight evenly. Think of the human body as it sleeps on its side. If that person were to lie on the ground on their side, the waist would sag down because there wouldn’t be support, and their shoulders and hips would be elevated. If you were to look at their spine in this position, it would sag down toward the ground. Also, all of this person’s weight would rest on the shoulders and hips. Think of how long you can stand on your toes for. Your toes can’t bear the weight of your whole body for very long. Similarly, it’s not great for your shoulders and hips to bear the weight of your body all night. This person lying on the ground would likely wake up stiff and sore. 

The ideal mattress functions by allowing your shoulders and hips to sink into the mattress (comfort), while supporting your body, so that your weight is evenly distributed throughout your body and any pressure points are alleviated (support). 

The comfort layer is the upper layer on the mattress and fulfils the comfort function, to spread your body weight evenly. You should sink into this layer. It alleviates any pressure points. This layer is the one that you’re looking to hold you snugly (so it should conform to the shape of your body) and comfortably. This is the soft layer, made of foams or quilted materials. 

The support layer determines how deep into the mattress you go. This is the layer encased by the comfort layer. It keeps your spine straight by allowing certain parts of your body to go further down than others, and supports the parts of your body that need to rest higher up. 

These two components make up a system. The best mattress for you is about finding the best mattress system for your body within your budget. Knowing what makes up a mattress and how its different components work together will help you determine confidently whether this is the right system for you. 

The Comfort Layer / Upholstery Layer

Many beds have the comfort layer actually be made up of a few layers of material, to allow for customisation and to take advantage of different properties that different materials can offer. The three types of foam, latex foam, memory foam, and polyfoam are commonly seen in this layer. There are also mattresses with gel foams, and organic or natural fibres such as wool or cotton. The last category is the pillow top or euro top mattresses. These sit on top of the comfort layer, but should be included in this section of this article as that is the layer you are lying directly on. The manufacturers of pillow top and euro top mattresses claim that the extra layer provides a more comfortable sleeping experience, so we will briefly have a look at this type of mattress. 

Comfort Layer – Foams

Foams are very popular in bedding for their ability to conform to your body shape. By doing so, it essentially cradles your body so that the body weight is distributed evenly throughout the length of the sleeper. Memory foam in particular is great for side sleepers, because it is excellent at relieving pressure points by really conforming to your shape. You will feel like you’re sleeping in the mattress, rather than on top of it. You can think of it like a plaster impression of your body. However, memory foam is less durable and will sag much more easily. 

Polyfoam is similar to memory foam except that it is more responsive than memory foam. It’ll bounce back instantly. You want to make sure that the polyfoam is high density or high resilient foam, and of a good quality, otherwise durability and sagging will become a problem sooner rather than later. 

Latex foam because of how bouncy it is and how quickly it reverts back to its original shape, will be very helpful for those who move in their sleep a lot, and for those who have any difficulties with mobility. It’s firmer than memory foam so is better for stomach sleepers. You’ll feel more like you’re sleeping on top of it rather than in it. 

A gel foam mattress is memory foam with gel distributed throughout the foam. The gel mattress can be helpful for those who sleep hot, as memory foam by itself traps heat. Gels pull heat from the body into the core of the mattress. However, the gel particles can fall out of the foam, compromising the structure of the mattress. Gel mattresses are also available where there is a layer of gel near the top, which may prevent this problem. In both situations though, even though the gel is cool to touch at first, many people find that after some time it becomes hot again. This is because the gel simply conducts heat and does not exude coolness in itself. 

For more detail on how different foams have different attributes, check out this article

Comfort Layer – Organic/Natural Materials

Organic and natural materials can cover a wide variety of materials. The most commonly seen are latex foam, wool, and cotton, but many plant fibres and animal hairs such as horse hair and camel hair can be used as well. Latex foam was covered above, so all I’ll say about it now is that latex foam comes both in all natural, or as a synthetic latex. Of course, if you’re looking for a mattress made with natural materials, make sure that the latex foam in the bed you’re considering is actually natural latex, not synthetic latex. However, be aware that natural latex may not be organic. 

Natural materials such as wool tend to be fairly firm with a little bounce. There are no additives to soften the material, and over time the person’s weight will compact the bed more and more. The main benefit of organic or natural materials is that they don’t contain any synthetic chemicals which may lead to health problems and physical reactions, and they are better for the environment, being made from sustainable resources and being biodegradable. Some are more breathable than others (generally wool, cotton and coir), however latex foam is definitely not in that category. 

Micro Coils

Micro coils are exactly what they sound like – tiny coils. They’re often found in premium standard mattresses and are used in the upper comfort layers, and sometimes in the pillow top section of pillow top mattresses. These tiny coils aim to provide support and comfort the way that pocket spring mattresses do, by using coils that push vertically up and down to distribute your weight evenly throughout your body. 

Coils bounce back so this will prevent impressions of your body remaining in the bed, helping with durability of the mattress. There is also more airflow allowed through the coils than in a foam layer, helping hot sleepers stay cool through the night. 

Comfort Layer – Pillow Top / Euro Top

Pillow top mattresses don’t refer to the material inside the mattress, instead it just means that there is an extra comfort layer added to the top of the mattress. On most mattresses there is tape edging on just the top and bottom of the mattress. Visually, you can distinguish a pillow top from other mattresses because there is an extra tape edge, and between that extra tape edge and the top tape edge, you will see a stitched indentation all around the top of the mattress, so the mattress will look exactly like its name – a pillow top. 

The concept of a Euro top is similar. There are three tape edges rather than the normal two, but there is no indentation and so the mattress is straight from top to bottom.

Euro tops tend to be denser than pillow tops, and therefore slightly more durable. 

Some people will find the extra layer of padding and fluffiness to be more comfortable, particularly side sleepers. It’s very dependent on individual preferences. However, pillow tops will be less durable than other mattresses, and there will be sagging in the pillow and euro top faster than otherwise. 

The Core Layer / Support Layer

The core layer is the layer that offers support, hence why it is also known as the support layer. This can be some types of foam such as latex foam, or springs, or even water or air. Different materials in this layer will feel different to each other, so it will help to know how they differ.

Core Layer – Foams

Latex foam can be used both as a core or upholstery layer. It’s firm, resilient and can conform to the sleeper’s form, relieving pressure from the spine and neck. Latex, like a rubber ball, will bounce back faster than memory foam. It has a wide range of firmness choices and quality levels. There are two types of latex foam used in mattresses; Dunlop latex vs Talalay latex. 

These two types of latex are for the most part the same latex, made differently to produce very different results. Many mattresses will use a combination of the two latex foams to customise the softness and firmness of the mattress, and to determine how supportive the mattress will be. The Dunlop is very dense, which means it is extremely durable and very supportive. Hot sleepers though will usually prefer the Talalay as the dense Dunlop latex retains more heat.

Memory foam is rarely used as a core layer as it softens under pressure or with body heat. Polyfoam however bounces back very quickly, so does resist the weight of the human body, and in so doing supports it. So you will quite commonly find polyfoam used as a core layer as it can be very supportive, and can also be made to varying levels of firmness. Ensure that the mattress uses high density polyfoam (HD) or high resilience polyfoam (HR), as conventional polyfoam is not of a high enough quality to be a support layer. 

You may find that even if the core is innerspring or another kind of material, polyfoam is commonly used for edge support to keep you from sliding off the edge of the bed. 

Core Layer – Innerspring

With innerspring mattresses, whether they are bonnell spring or pocket spring, the body is supported by the springs. How firmly the springs push back to support the body depends on a number of factors, including the coil or spring count (the number of springs in the bed), the working turns (or how tightly wound the coils are), and the coil gauge (or how thick the wire is). If more of your weight is spread out over a larger number of springs, each coil is individually bearing less of your weight so the more supportive it can feel. If the coil has more turns, there is more wire in each coil supporting you, so again it can be more supportive and firm, so it is with a thicker wire (indicated by a lower coil gauge). The way the coils are laid out, such as whether they are connected or independently standing coils, will change how the springs bear your weight as well and support you. Coils that are connected to each other will distribute your weight further throughout more coils, rather than independently standing coils where your weight pushes down only on the coils that are directly holding you up. 

Core Layer – Water

Waterbeds are comfortable. It’s like sleeping on waves, which many find soothing. Water conforms to the shape of the sleeper. Some people feel that waterbeds reduce pressure points, improve blood circulation and encourage spinal alignment. Others however feel that it doesn’t support the joints, leading to back pain or even numbness. 

Core Layer – Air

An air mattress can actually help people with back problems or other joint pain, or bed sores in particular. The main reason for this is that the firmness of the bed can easily be adjusted. For a firmer bed, add more air. For a softer mattress, deflate it slightly. For many people though, an air bed just isn’t that comfortable. It doesn’t have the support that a classic bed can offer, and you compromise firmness for a mattress that conforms to your shape by deflating it slightly. 

Core Layer – Organic / Natural Materials

In many natural mattresses, latex foam will be used for the support layer, sometimes with an added layer of coir, or innerspring mattresses (usually bonnell spring rather than pocket coils which use polyester pockets to encase each coil). 

Some niche manufacturers will make mattresses completely out of wool, or organic cotton. Those mattresses made entirely out of wool or cotton will tend to be firmer. Another material which can be used in the core layer of organic mattresses is coir, the fibres from coconut husks, which can also be quite firm. 

Final Thoughts

The best mattress for you is about finding the best mattress “system” for your body within your budget. Knowing the composition of mattresses, and how the placement of various materials throughout the mattress can change how a bed works, can help you understand better what kind of system you’re looking for. Try a variety to get an idea for what feels more comfortable for you, and then you can confidently further narrow your bed search down from there.

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