We spend nearly a third of our lives sleeping, according to the U.S. Centers for Disease Control and Prevention. It’s a vital part of our day, so a bed is important. Yet mattress prices range from sub-$100 to over $10,000, and nobody really knows what they want in a mattress.
Our ideas of “soft” and “firm” are more complicated than we think. A “firm” bed can still feel soft because it has a top layer that allows us to sink in, contouring to our bodies. Meanwhile, a “soft” bed can just be cheap core materials. Adding to the problem, the mattress industry is filled with buzzwords, and the saga of Sleepopolis is a sobering reminder of how competitive and cutthroat it really is.
Don’t Sleep on the Truth
If you’re not aware, the original owner of Sleepopolis was sued by Casper, its new owner, over reviews and marketing money. You don’t know who you can trust in this industry or who’s taking money from whom. Even the independent organizations inevitably have to work with the mattress companies to avoid lawsuits and takedown notices.
Read this guide before buying your next mattress, and you’ll find you know more than the salesperson. That’s because retail employees typically learn everything about products from the brand representatives. These representatives sell them on all their marketing buzzwords, sleep studies, and patented technologies.
But if you don’t understand what you’re looking at, the last person you should be asking for information from is the one trying to sell it to you. That’s how consumers get fleeced.
So let’s start with a break down of the important parts of a mattress.
Anatomy of a Mattress
Mattresses are made of multiple layers that fall into three basic categories: Comfort, Support, and Transition, which is a hybrid of the two. These layers serve different purposes, and the combination (or lack) of layers is what ultimately determines how “soft” or “firm” your mattress really is.
Support Layer – The support layer is the foundation or core of your mattress. Basically, the support layer is in charge of carrying all the weight placed on the mattress, so it determines the “lift” and “springiness.” The construction of the support layer should encourage spinal alignment, allowing heavier parts of your body to press down without adversely affecting other parts.
The support layer provides buoyancy, keeping your body “afloat” on the mattress.
What this means is if you’re sleeping on your side, your hips and shoulders (the widest parts of your body from the side profile) should easily sink down. Meanwhile, your head, neck, legs, and midsection should be well supported. As you roll over to sleep on your back or stomach, the support needs change, and the transition between the two should be seamless.
We’ll talk more about the types of support cores used in the next section, but for now know that the support layer is responsible for the heavy lifting. It gives the mattress lift, cradling your body above the frame in whatever position you want to be in.
Comfort Layers – Comfort layers are where a lot of the marketing can come in, and the basics you need to know revolve around contouring. While support lifts you up, the contouring of the comfort layers should form a mold around your body to increase the amount of surface-to-surface contact between your body and your mattress.
This contouring is what you think of when you hear a mattress described as “soft,” but it’s an important feature for “firm” mattresses too. If you removed the “soft” contouring from a “firm” mattress, you will wake up with sore parts of your body. That’s because those parts were doing all the heavy lifting while you were sleeping. Imagine sleeping in one of Kino MacGregor’s Ashtanga yoga poses.
How tired would your hands, wrists, shoulders, and arms be after holding the entire weight of your body up while you slept for 8 hours?
Without comfort layers, that’s basically what you’re doing to your body, and that’s why you’re waking up with stiff muscles, a crick in your neck, your arm or foot asleep, and other issues. Comfort layers are responsible for the feeling of sinking into a mattress, which is different than the lift provided by the support layer.
In short, the support layer is like pushing a key on a keyboard, providing up-and-down motion and support. The comfort layer is like putting your finger in a glass of water, having it envelope and surround every submerged cell.
Comfort layers also include all the “technologies” typically mentioned in mattress marketing. These include cooling gels, microfiber, pillowtops,
The final piece is an optional layer called the transition layer. The transition layer is placed between the comfort and support layers to absorb the energies of both and keep the bed stabilized during movement. Transition layers are responsible for you being able to move without your partner on the other side feeling it.
Not all mattresses have transition layers, and they’re rarely included in sub-$250 models.
The Soft vs Firm Debate
So with all this said, the terms “soft” and “firm” are used very loosely and are referring to a wide array of different factors. If you ask a mattress salesperson to recommend a “soft” or “firm” mattress, be sure to also ask what makes each mattress “soft” or “firm.” You’ll almost for sure get a bullshit answer. But at least watch to see if they pull it out their ass or just point you to the marketing materials, which aren’t always helpful either.
First, the tension of the core and the support layer’s construction can make a mattress feel softer or firmer. You can use a rubber band to test these physics. When it’s loose, a rubber band will be very “soft,” making it pliable, elastic, giving to weight/pressure, etc. As you stretch the rubber band, it becomes more “firm,” giving much less elasticity, and refusing to move when weight/pressure is applied.
All types of mattress cores can be manufactured with varying degrees of tension to create a full spectrum of firmness levels. And that’s not all – as I mentioned above, adding comfort layers can make a bed feel more “soft” and the lack of comfort levels can be perceived as “firm.”
In addition, overstuffing the mattress lining can create the perception of firmness, just as understuffing it (i.e. using less materials and cutting costs) can make a mattress feel more “soft.” Even a more tense fabric can create a firmer mattress.
Ultimately, what you’re looking for in a mattress is one that supports your body weight while contouring to your body to maximize surface area of your body touching the mattress. From there, it’s just a matter of finding a mattress that fulfills your needs and you can afford.
Of course, the biggest differentiation used when mattress shopping is the core, so let’s dive into those next.
Types of Mattress Cores
As you browse mattresses online or in store, you’ll them most often described by their cores. Innerspring, foam, latex, air, and water are all used to make cores for a mattress support layer. Each can be engineered to provide softness or firmness, so the differences are mostly up to personal preference. Here’s what they’re all made of.
Innerspring – Innerspring mattresses use coils to create the core, and they’re often paired with a boxspring foundation. Innerspring cores are constructed in one of four ways:
- Bonnell – This is the entry-level innerspring construction. Bonnell coils are the oldest spring technology, using a knotted, round-top, hourglass-shaped steel wire coil. The individual coils are laced together to form the innerspring core.
- Offset – A step up in quality, Offset coils are similar to Bonnell coils, but the top and bottom convolutions are flattened. The flat segments are then hinged together with helical wires.
- Continuous Coil – Continuous coils use a single wire to form all the coils, creating a similar hinge effect to offset coils. This construction is used by certain manufacturers for special models.
- Pocket Coil – Sometimes known as Marshall coils, these knotless coils are individually wrapped in fabric pockets. Each coil works independently, minimizing movement of the other coils and increasing buoyancy.
Softness and firmness in innerspring mattresses is controlled via the gauge and tension of the wire. Some companies will pre-compress coils in advance to increase firmness. The amount of coils and construction used also affects the feeling of firmness.
Foam – Polyurethane foam (aka polyfoam, poly, or foam) is becoming more popular in the 21st century as a mattress core. It gained popularity when mattress-in-a-box companies like Casper, Eight, and Purple popped up.
Polyfoam was initially popularized by Tempur-Pedic’s Swedish memory foam mattresses in the 1990s. Memory foam is a comfort-layer foam formulation, and cooling gel (discussed below) is often injected into the comfort layers with varying levels of success in lowering mattress temperatures.
Foam density is is a major factor in its firmness, and there are three different grades of foam legally used in mattresses:
- Conventional Polyfoam – The lowest grade of foam has a density less than 1.5 pounds per cubic feet (PCF). If you bought a $100 foam mattress, it’s likely made of low-grade conventional polyfoam. This foam degrades faster and will lose its sponginess and bounce with frequent use over time.
- High Density Polyfoam – High-Density (HD) polyfoam is the mid-grade foam used in mattresses. HD foam is at least 1.5-PCF density but less than 1.8. If a foam mattress is not at least 1.5-PCF density (1.8 is preferred), it will not last and will soon become lumpy.
- High Resilience Polyfoam – High-Resilience (HR) polyfoam is the highest grade of mattress foam. HR foam has a density between 1.8 and 2.4 PCF, and it’s much more durable and elastic than other foam types.
Foam mattresses are constructed in layers, with 4 to 8 inches of the firmest foam in the foundation, followed by an inch or two each of increasingly softer foams, including the coveted memory foam, which is actually more dense than polyfoam, at 4 to 5 PCF.
Firmness of foams are also measured in either indentation force deflection (IFD) or indentation load deflection (ILD). This measures the top layer’s ability to conform to your body and create the impression of firmness.
Latex – Latex shares very similar properties to polyfoam, but it’s naturally produced, whereas polyurethane is synthetic. It’s also springier, with a more rubbery feel, making it a somewhat more durable. Like polyfoam, latex can be made with a wide array of tension and firmness.
Latex is resilient and more durable than polyfoam, and it’s also more expensive. This means an all-natural, high-quality latex is your best bet, but it’ll likely set you back several thousands.
Air/Water – Air and water have natural buoyancy when trapped in a pliable bag, so both have been traditionally used in mattress construction. My ReST mattress uses air pumps and air pressure to adjust the firmness and support in different zones throughout the bed. So don’t think it’s just Walmart air mattresses used in camping, as ReST is a very high-end mattress.
Waterbeds will likely make a comeback one of these days, but for now, we just associate it with lonely mustached bachelors in the 1980s.
Hybrid – Most mattresses you’ll find on the market are hybrids. They use a blend of each of the technologies above, such as an innerspring core with a memory foam top. My ReST mattress is actually a hybrid, as it has several layers of HR and memory foam on top an adjustable airbed transition layer, and a solid HD foam base.
Even foam mattresses are often layers of polyfoam and latex in different densities, which makes may of them hybrids.
Mattress Industry Extras
Let’s not forget the extras promised in mattresses that drive up the prices. You’ll see tons of fancy buzzwords with TM and R signs after them. There are the proprietary sleep technologies that mattress companies say differentiate themselves from each other, so let’s look at a few common extra features.
Cooling Gels – Cooling gels have commonly been used to cool the ground we walk on, and these synthetic gels are now infused in foam mattresses to help with heat dissipation (think of the gel you use on a computer CPU chip). The usage of this gel has been shown to lower coil or air hybrid mattress temperatures, but full-foam or latex mattresses with cooling gel can actually run hotter.
Pillowtops – Pillowtops add an extra layer on top that makes people feel extra. Padding in this “pillow” can be made from polyfoam, latex, batting, or a mix. Critics of the pillowtop cite its lack of durability and the fact that fitted sheets can decrease perceived softness by flattening the extra mattress thickness.
Memory Foam – Memory foam is low-resilience polyfoam with viscoelastic properties. It molds easily to your body, making it an ideal comfort layer material. As memory foam ages, its ability to return to normal is greatly reduced.
Adjustable Beds – Adjustable beds are actually controlled by the bed frame. They hinge in the middle and the top half can be adjusted to varying degrees of incline using a remote, much like a hospital bed. Because each side is controlled individually, adjustable mattresses will be two twin-sized mattresses next to each other, rather than one large king-sized mattress.
Smartbed Apps – Smart beds are the latest in smarthome technology. Companies like Eight and Rest offer connected features so you can adjust support, temperature, and even trigger smarthome events through your bed. These extras are relatively new to the market, so the technology is expensive and not widespread yet.
Which Bed to Buy
Now that we know everything, the question remains which bed to buy. What you want is a bed that feels comfortable to you when you lay in it. It should support your body and keep your spine aligned. A good mattress should be made of high-quality materials that will last a long time, and it should be easy to replace with a solid company support plan.
You should be able to find a great bed in the $500 range with enough due diligence. Just be sure to ignore the marketing buzzwords and focus on what’s really important when buying a bed. And don’t be afraid to use this guide, or anything else from your research, to haggle with the salesperson. The mattress industry has high markups with a lot of lower quality materials being passed off as something they’re not.
Knowledge is power, and you are now armed to shop for a new mattress with confidence. Good luck.