What is in a mattress?

We’ve come a long way from the straw-filled mattresses of yesteryear: today, the surfaces we sleep on are highly-engineered and personalized to provide people with the best rest possible.

In order to come up with the very specific design ideas, we create most designs with the assistance of state-of-the-art AI interior design software.

In this article, we’re going to dive into the various types of mattresses out there, exploring their various fillings and the ways they provide comfort for your beauty sleep. While some of today’s mattresses come equipped with temperature control, variable firmness, and even sleep data analytics, your sleep is often only as good as what your mattress feels like. Whether we’re talking springs, foams, water, or horse hair, there is a mattress out there with the filling that is right for you. Let’s dive in.

The first mattress and the evolution of the sleeping surface

Before we get fully into the composition of our modern and commonly-known mattresses, let’s chat about a short history of the mattress and how it’s evolved into the daily necessity we know today.

Sleeping structures are different across the world and the mattress has a bit of cultural and geographic variation. While someone in North America will hear mattress and think of a large, plush surface to snooze on, they might be in for a bit of an awakening if they ever visited Japan and spent some time sleeping on futons (which are really comfortable for anyone who’s curious). In Europe, divans have the dual purpose of being a place to sit and relax but equally converting into a sleeping area if they so desire (seems a bit modular doesn’t it?) With these structural variations, their fillings have historically varied as well, ranging from metal springs and cotton to foam rubber and water bladders. We’ll dive fully into these later and check the list for all possibilities. For now, a bit of history.

While we may have the impression of our mattresses, made with memory foam and now coming with remotes and mechanical parts, as cutting edge inventions of modernity, the truth is a bit different. In fact, even before humans were the humans they are today (Homo sapiens), some of our predecessors in the genera of hominid were starting to sleep on the ground, heralding the way we’d sleep forevermore.

It is generally accepted that Homo erectus, sapiens’ predecessors, were likely the first hominids to sleep on the ground. Before erectus, our smaller, more chimp-like evolutionary ancestors would be able to hide and sleep in the trees, evading nighttime surprises by nocturnal predators. By the time the taller, more upright erectus rolled around and started playing with fire, the notion of sleeping on a flat surface became more possible. The fire would help one’s immediate surroundings stay visible and could even aid to ward off any creatures that would maybe hope to have a midnight snack. Furthermore, it was probably comfier than sleeping in a tree.

Now, this isn’t to say that the ground is a mattress – while a taxonomic discussion had by intoxicated teenagers may eventually deteriorate to that (if you think about it, isn’t any surface you can sleep on really like a mattress, dude?) the earliest physical evidence of humans sleeping on man-made structures built for comfort dates back over 77 000 years.

In 2011, the oldest known mattress was dug up in South Africa; It was built largely out of reeds and rushes, buried under bedding made from squished and compacted leafy vegetation. It was discovered within a cave site in the South African province of Kwa-Zulu-Natal; the site itself seemed to be a popular place to sleep, where the vegetation bedding had seemed to accumulate over 39 000 years. At the very bottom, underneath these proto-mattress fillers, was a 77 000-year old structure filled with greenery – likely quite soft when in use – physical evidence indicating some of the first sleeping surfaces we might recognize today.

There are a few interesting features about this mattress that seem to make a lot of sense. For one, through the layers of compacted and fossilized plants, there is significant evidence that indicates that the mattress was periodically burned and exposed to high heat. This is likely in the aims of limiting pest infestations, smells, and bits of trash that make it into the bed (ever had a midnight snack while watching TV in bed and all of a sudden you’re sitting in crumbs? You may be closer to your relatives from nearly 100 000 years ago than you think). This mattress was about a foot high off the ground, and 22 square feet large. While the modern California King size mattress may dwarf the earliest mattresses we know of, this massive proto-mattress was likely built to house the whole family. In the Stone Age, hunter-gatherer people would all sleep together based on the social structure of their family groups: it kept everybody warm, kept everybody close (in case a predator snuck in somehow), and it likely made people feel happy and safe. While cuddling between my siblings, parents, and grandma sounds a bit nice, I’ll admit I’m a bit used to being able to stretch out in my bed and may prefer that instead.

Even more interesting is that the researchers saw the ‘top sheet’ of the mattress was made with unique types of vegetation that differed from the compositional elements of the sleeping surface itself. This ‘top sheet’ would be made of insect-repelling plants and leaves, likely to keep mosquitos and big flies away from you while you snoozed. This plant, the river wild-quince, produces chemicals that kill most pests and our early ancestors would make full use of it in order to get a good night’s sleep. When you sleep outside like our hominid ancestors did, body lice and mosquitos become a real issue, so this was a great solution to a universal problem. Additionally, according to the researchers, this may also represent a very early medicinal use of plants by human beings.

We fast forward many, many years later. Mattresses in their proto-form would emerge all over the world, most notably in ancient Egypt. About 4000 years ago, Egyptians began building raised wooden surfaces to sleep on, likely to avoid pests and creepy crawlies on the ground (snakes were an issue!). Variations in materials would inevitably come up in order to inevitably create some sort of socioeconomic division around something as universal as sleeping, and we begin to see evidence of bedframes and mattresses made of ebony detailing and bejeweled bases. On top of these raised structures would be wool and linen bedding upon which you could rest your weary self. On the sides were raised supports made of wood or stone, the earliest pillows we can really start to imagine!

In ancient Rome and ancient Greece, a similar model of bed would emerge filled with hay and reeds, some even made with feathers. Sheets and blankets were commonplace in these societies, and beds became a place for socializing and eating as well as sleeping. We see early “klines” – like couches with a single headboard – all throughout Hellenic and Roman imagery from the era, combining comfortable mats with a place to rest casually and chill.

The word mattress itself is likely derived from the Arabic “matrah”, denoting a place where ‘things are thrown down’. By the time of the Crusades, people in that area of the world where long-enjoying the comforts of mats for sleeping and sitting. Europeans would see this and take it home in a similar manner, adopting the floor mats and cushions on the floor for comfort and rest. The world would slowly evolve into materas and make its way into the Romance languages and then Middle English. After that, the rest is seemingly history.

Mattresses would continue to be normalized throughout the Western world, being stuffed with straw and vegetation if you were poor, linens and feathers if you were rich. Bed frames began to emerge as depictions of class and wealth, with ornate wooden carvings decorating the bases and sides of the nobility’s sleeping surfaces. By the end of the Medieval era, down mattresses would become more common as a filling for all sorts of people. Coil springs would emerge in the mid-19^th century, providing durability and uniform firmness throughout the mattress. By the 20^th century, mass-production was increasingly popular and began to feed the growing middle classes – out of this demand would emerge taste, variation, and preference of your sleeping surface. It’s not a far leap to get to where we now are, where mattress preference extends into hundreds of brands, dozens of styles, as many sizes as you can imagine, and so many kinds of fillings to make your sleeping experience your own.

DIFFERENT KINDS OF MATTRESS FILLINGS

While we’ve come a bit of a distance from the reed and leaf mattresses of our ancestors 70 000 years ago, let’s take a look at the many different filling options you can choose from today.

Ticking Mattress

While the name may evoke a bit of a scary image, it actually has nothing to with the bloodsucking bugs. These beds/mattresses derive this name from the tightly-woven material that is structure of their main compositional filling. These strong, stiff weaves are known as ticking, which are really cloth bags that can be stuffed – without the filling, they have no inherent structure and thus are often referred to as bed ticks. These ticking bags are then stuffed with any sort of possible soft filler to give it a comfy base.

In a lot of ways, the ticking mattress is probably the oldest form of mattress we can recognize around the world. Furthermore, most futon sleep situations and layered mattresses are usually made from stacking ticking mattresses. Before large-scale production, ticking bags would probably be homemade and stuffed with readily-available materials in the area. As such, it would be the most accessible type of mattress that would emerge. The variation in these types of mattresses comes out of the filling material. A bed tick filled with straw would be called a pallet or paillasse, a bed tick filled with loose fibers like cotton or wool (flock) would be called a flockbed, and a bed tick filled with feathers would be called – understandably – a downbed.

The filling in these beds can often bunch up, so most tick mattress owners have to air out, shake and smooth their mattress every morning after getting up. For the comfiest sleep, people would stack their ticking mattresses with the softest material on top. The result is what is likely a surprisingly-comfy sleeping situation, albeit not very ergonomic in the long run.

Latex

Latex is a material that is made from the sap of the rubber tree and is found in many different widely-available goods. In mattresses, latex can be used in its foam form which is created by incorporating air and compressing the sap extract. Latex mattresses are considered valuable for their gentle contouring and ‘bounciness’. The breathability of this material is a prime selling point for those that sleep with high temperature.

These are highly responsive mattresses that many swear by, but they tend to conduct a lot of movement throughout the mattress which can make sleeping on them a bit of an issue if you snooze next to someone that is a bit restless when they’re off in dreamland. However, upon further inspection, it seems like the movement isolation features of these kinds of mattresses are quite dependent on the actual construction and design of the specific mattress in question. From what I’ve seen, all-natural latex mattresses can actually be very effective at reducing disturbances. Equally, these mattresses are very long-lasting and even biodegradable. Pretty neat!

There are a number of ways latex mattresses can be created, usually broken down into synthetic and all-natural latex. While we know all-natural well, synthetic latex has a number of benefits as being able to adjust certain specific features of the latex can allow the mattress to more specifically suit its users. There are mattresses that incorporate both and even mattresses that use latex as a shock-absorbent base upon which foam or springs (or both) can be placed.

The main disadvantage of this type of mattress is its firmness and compression. In regard to firmness and compression, this can mean that some users of the mattress might start to feel firm spots where they need it to be soft and soft spots where they need it more firm. As the latex begins to form to the user’s body shape, over time that shape will be imprinted into the latex and may be difficult to reverse. Equally, the all-natural latex mattresses are quite expensive, especially when compared to the foam and spring ones that can be commonly found.

Innerspring/Coil Mattresses

The innerspring! We all know it, we’ve all slept (or still do) on one. They are made up of two main components: the spring core in the middle and the upholstery layers sandwiching it on both sides.

They’ve been in production since the 19^th century and are still extremely popular today. They are well-liked for their even support (as long as the springs stay happy). They are very responsive, bouncy beds with plenty of customizability: different spring tensions and varying types of upholstery can be very good at making the perfect mattress for your own needs and comfort criteria. Furthermore – given their high production – they are usually reasonably priced.

The core of the mattress is the main support of the bed. This core, also known as the innerspring, is made up of large steel coil springs. These coils, if they’re not encased in their own support, are interconnected throughout the bed laterally by wires, ensuring that the springs only fold vertically to avoid bending the springs to the side and creating areas of discomfort throughout the bed. Equally, these springs can pop out of place or the wires can break, resulting in divots and lacking support in certain parts of the bed, something some of us have experienced (and it sucks).

The coils themselves have various gauges to determine the firmness of the mattress, changing in increments of quarters. The lower the gauge, the firmer the spring and as such, the firmer the mattress. Traditionally, most mattresses vary from 12.5 – 15.5 gauges. There are four different kinds of coils that can be found in most mattresses. The first, called Bonnell coils, are the oldest ones we know and were adapted from the springs in cars from the 19^th century. When placed in the mattress and connected with horizontal wires, they form the innerspring body called a “Bonnell unit”. These springs have a round top and are hourglass-shaped.

Next, we have what are called offset coils. While they have a similar hourglass shape to the Bonnell variety, certain portions of the top and bottom of the coil have been flattened and create a bit of a hinging effect when all connected in the entire innerspring unit. These are also connected with horizontal ‘helical’ wires like the Bonnell. The last non-encased coil variety is called the continuous coil, which means that the entire innerspring body is built out of a single piece of wire. This gives lots of even support and can help prevent one spring from being damaged and ruining the entire mattress. These are also known as “Mira-coils”.

The last coil is the encased coil, also known as wrapped coils, pocket springs or Marshall coils. These springs are far thinner than the ones in the models we’ve seen thus far and shaped like barrels as opposed to hourglasses. These hourglass-shaped coils are wrapped in a fabric pocket of a non-woven fiber (to prevent ripping) and maintains a bit of an upright position. As such, it doesn’t need to be interconnected with helical wires and can compress independently from the other coils. This has an interesting effect which means that your body and weight on the mattress will be directly addressed by the coils it’s affecting. They can help isolate movement across the bed and are likely quite a bit more comfortable than their counterparts. Most consumers, according to the wiki, prefer this kind of coil mattress to almost any other kind of mattress.

Now that we have the innerspring figured out, the last thing to address is the sandwich: the upholstery layer keeps everything together and offers the cushion and comfort of your mattress. You have your base from the mattress’ core, now you fluff it up to make it comfortable. The upholstery layer is made up of insulating fabric, middle upholstery, and the ‘quilt’ on top.

The insulator is self-explanatory and just separates the soft fabric of the middle upholstery from the innerspring core. It is made up of mesh or fiber and is just meant to hold everything in place. Next up is the middle upholstery and this is where the comfort of the bed really comes in. The materials can thus vary massively: often you have foam or fiber pads that can allow your body weight to sink in and still be supported by the core. There are also many modern mattress companies that are using ‘gel-infused foams’, which involves pouring gel into the upholstery foam to give lots of sensitivity and squishiness. Lastly is the quilt, the piece that we see only when we’re changing our fitted sheet and mattress covers. It is usually made up of soft materials that are stitched to the main ‘ticking’ structure of the mattress.

Foam Mattress

The foam is a cool mattress that has emerged in more recent years of sleep technology (compared to the inimitable ticking bed or innerspring design). Funny enough, this kind of tech was developed by NASA scientists in the 1970s, who were hoping to improve safety features and seat comfort in modern airlines and spaceships. They discovered that these foams were highly responsive, variable in different temperatures, and retained their shape after they were compressed. This material was publicly released in the 1980s and the first foam mattresses were used in hospitals to help reduce pain for immobile patients. By 1991, consumers across the world could purchase their own memory foam. While our modern airline safety features are now (hopefully) a bit past foam cushioning, they have made their way into the mattress industry in a big way. Foam mattresses are now a popular and viable choice for anyone, especially those with chronic pain and joint issues.

The foams used are varied depending on price point and manufacturer. There are polyurethane foams made from petrochemicals, memory foams (viscoelastic), and latex rubber foams which we looked at earlier. As they are a bit different I felt they required their own section. Foam mattresses are also often used with a base to provide a hard, underlying structure by which the foam can really shine.

Memory foam mattresses are also made using a combination of foams available on the market. A viscoelastic foam, which retains and conforms to the shapes of the weighted objects on top of it, is placed overtop of polyurethane foam that offers a bit more structure. Firmness and responsiveness can be modulated given on the thickness and air pockets inside the foams chosen. People really like these kinds of mattresses because they give very specific kinds of support on joints and limbs. This also explains their price point in some contexts: they are highly technical and often built to unique specifications for their consumers and start ramping up in cost with the more tech they use. Because they become firmer in cold temperatures and more supple in warm temps, people can often fine tune the way they sleep by choosing a specific kind of foam mattress.

Equally, these mattresses can run a little hot given their density – manufacturers have responded to this by innovating in various features of the foam, creating small holes throughout the mattress, infusing the foam with gel, or reticulating the pattern of foam in order to create space for air to travel through. There is also high-density foam that is significantly more compact than the memory foam we’ve looked at. They provide more of a structure than their counterpart and can usually last a bit longer.

Bladder Mattress

Another weird mattress name, but like the ticking bed there’s no real connection. Well, I lied a little, there is evidence of Persian mattresses and cushions from 5000 years ago made out of goatskin bladders filled with water. In our context however, the bladder just denotes a chamber filled by a fluid, liquid, or gas. This is where our air mattresses and waterbeds come in to shine, providing conductivity and comfort at relatively accessible prices.

The air mattress is one we know well. I personally have had plenty of experience on them crashing at friend’s places or at temporary sleep situations. In the first apartment I ever lived in, my 3 other roommates and I pushed two air mattresses together and the 4 of us slept on this Franken-bed until our furniture arrived 3 WEEKS LATER. It was a snug sleep every night. Furthermore one of the air mattresses had a slight leak so two of us would wake up around 4-5am every morning laying on the hardwood and would pump up the mattress with a foot pump, wiping sleep from our eyes. To keep it fair, every night we would cycle who was sleeping on the leaky bed to ensure everyone experienced the 5am hardwood wake-up. As 19-year olds out of the house for the first time, it was an intimate taste of the real world. I’m surprised we didn’t kill each other, but thankfully we actually lived together for 3 more years and are still amazing friends to this day. After our furniture arrived we pushed the air mattresses against the wall and used them as a makeshift sofa until we had enough money to buy a coach. Beautiful memories. Anyways, back to the air mattress.

If you’re wondering what an air mattress is filled with, I… I’m not sure what to tell you. It’s filled with air. These are excellent temporary beds as when deflated they fold up very small, making them ideal for camping (or for waiting for furniture for three weeks in an empty apartment). These mattresses vary in terms of price point and intended use. Most of the ones I’m experienced with are a single ‘bladder’ made up of very strong rubber or latex, but there are many that are built with multiple air chambers to provide varying levels of support throughout the structure. Camping mattresses come with lots of tech including self-inflation and ultralight compositions for reducing backpack weight. I’m a big fan of the classic Therm-a-Rest.

Air beds also have a lot of practical applications and variable pressure air mattresses are used often for people with chronic pain and patients in hospitals to avoid bed sores. The variable firmness that is allowed with an air mattress can make the sleeping situation highly-personalized and thus is very valuable in specific contexts.

Lastly, the waterbed, which I feel thankful to have never really experienced other than in the context of raunchy 80s college movies. As the name suggests, these beds are filled with…. water! No surprise there, but they are supposedly quite useful and comfortable for those with spine issues. They have levels of variable support that many other mattresses do not, making them viable options for the individual with specific sleeping needs (and access to lots of water). They are often lined with fiber on top and below the water bladder to increase comfort and reduce the slosh-factor. Personally, all I can imagine is accidentally poking it against something sharp and turning your bedroom into a wading pool. Not worth the risk for me.

The future of mattresses: smart beds

And now, having seen the pantheon of mattresses and their various compositional elements, a new herald of the future emerges, a synthesis of all that came before and indicative of what is to come. In the last decade there has been an emergence of Smart Beds in the medical and consumer realms. These hyper-modern beds take all the pros of every mattress material you’ve seen above and attempts to make it fully accessible and customizable.

In a typical cutting-edge manner, these smart beds can control all features of your sleep. Regarding temperature, there are models of smart bed that can be remote controlled from a phone application. For a chilly night, one can turn the heat up a little bit without the need of any plugged-in blanket. For those of us that run hot, a smart bed offers the personalization of having a cool bed every time. Imagine this: a warm bath, a little glass of wine, and boom: a cool bed. Sounds like paradise, and probably comes at a price point reflecting this huge luxury.

Smart beds can also modulate the firmness of your bed and allow it to be varied based on your preference. This means that an individual doing lots of exercise who might be going to bed sore can make it softer after high-intensity workouts, while keeping a firm sleep for their off days. Or even more amazing, you and your partner can have variable firmness in your beds. This is genuinely mind-boggling, has so many applications, and might even save a few marriages.

To tie it all together, many of these mattresses come with sleep analytics and data you can access right from your phone. Rolled over a few times last night? Logged. Slept like a log for 10 hours and stayed in REM sleep the whole time? Logged. Your partner kicked you four times because you were snoring? Definitely logged. This sort of data can help you improve your sleep schedule and learn more about the way you rest, which has innumerable benefits. While the price of these mattresses serves to reflect their cutting-edge nature, by the time these beds become more accessible, the foam, bladder, and coil mattresses of our present will quickly be the bedding of the past, like our 70 000 year old reed mattress. Instead, only one kind of mattress will be needed that can accommodate to any person and any sleep style. Pretty neat.

Sleeping soundly and snoring loudly, this is Graham. Thanks for reading.