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The topmost layers of a mattress are known as ‘comfort layers’; collectively, these layers are referred to as the bed’s ‘comfort system.’ Comfort layers provide ample cushioning that provides a padded barrier between the sleeper’s body and the firmer materials found in the support core of their mattress. Additionally, comfort layers may offer other benefits, such as pain and pressure relief, motion isolation, and/or better temperature neutrality and cooler sleep.
Today’s mattresses are constructed with a wide variety of comfort layer materials. This guide will look at common attributes and functions of different materials used in comfort systems.
Although measurements vary, most mattresses have comfort systems measuring between one and five inches (1″-5″) thick. Technically speaking, most mattresses have three types of comfort layers:
The comfort system also includes the mattress cover. Most covers are made of fabrics or fabric blends. These may be natural fibers, such as cotton or wool, or synthetic fabrics like polyester, rayon from bamboo, or lyocell.
Comfort layers are important for sleeping for the following reasons:
Next, let’s look at the most common materials used in today’s mattress comfort layers.
Flexible polyurethane foam, also known as polyfoam, is a synthetic material derived from polyol and isocyanate petrochemicals. Historically, polyfoam comfort layers were used in the vast majority of mattresses – particularly innersprings. However, the growing popularity of alternative materials such as memory foam and latex has resulted in fewer all-polyfoam beds.
Polyfoam comfort layers may take one of two forms. Uniform layers have a flat, even surface, while convoluted layers have ridges that create a textured feel. Uniform polyfoam is usually found in the quilting and middle upholstery layers, while convoluted polyfoam – also known as egg-crate foam – is usually found in transitional layers, though it is rarely used in mattresses. In addition to mattresses, convoluted polyfoam toppers are fairly common.
Polyfoam is generally considered the lowest-quality material for comfort layers because of its relatively low density. It will not conform to the sleeper’s body as closely as denser materials such as memory foam or latex, and polyfoam’s composition often causes it to deteriorate quickly; this causes indentations to form in the sleep surface, leading to uneven support. Three grades of polyfoam are available: high-resiliency (HR), high-density (HD), and conventional. The table below breaks down each grade based on density, which is measured in pounds per cubic foot (PCF). Another factor to consider is compression modulus, which measures stress-to-strain ratio.
|Polyfoam Grade||Trade Name||Density Range (PCF)||Compression Modulus|
|Low-grade||Conventional||Less than 1.8 PCF||2.0 or lower|
|Medium-grade||High-density (HD)||1.8 to 2.5 PCF||2.1 to 2.3|
|High-grade||High-resiliency (HR)||More than 2.5 PCF||2.4 or higher|
Please note: According to the International Association of Bedding and Furniture Law Officials (IABFLO), any mattress sold as HR polyfoam must have a density of at least 2.5 PCF and a compression modulus of at least 2.4.
Polyfoam also absorbs a fair amount of body heat from sleepers, causing it to sleep uncomfortably warm. For these reasons, polyfoam is most often used in tandem with memory foam, latex, minicoils/nanocoils, and other, higher-quality comfort layer materials. Off-gassing is another issue; polyfoam beds are associated with stronger-than-average odors when new, and the smells can be persistent and/or excessively strong. However, all-polyfoam mattresses also carry certain advantages. For one, they isolate motion transfer fairly well and do not make any noise when bearing weight. They are also fairly affordable compared to other mattress types. Keep in mind that a mattress with one or two comfort layers, along with other comfort materials like memory foam or latex, will usually be more expensive than a mattress with 100% polyfoam layers.
Lastly, green certification is an important consideration for polyfoam mattresses. Most models carry the CertiPUR-US® certification, which is awarded by a nonprofit organization named the Alliance for Flexible Polyurethane Foam, Inc. The certification ensures the foam doesn’t contain mercury, lead, heavy metals, formaldehyde and other hazardous materials, and that the manufacturing process produces low volatile organic compound (VOC) emission levels.
Memory foam (also known as viscoelastic foam) is a specialized polyfoam material developed by NASA engineers in the 1970s. Memory foam is designed to become softer when it comes into contact with body heat, allowing the material to contour to the sleeper’s body very closely and consistently without sagging. When the sleeper gets up, the foam cools and returns to its original, uniform position. Over time, memory foam adapts to the sleeper’s body and will return to an ideal conforming position whenever he or she gets into bed. In addition to mattresses, memory foam is widely used in pillows and mattress toppers.
Many mattresses have comfort systems that are completely comprised of memory foam. Others feature memory foam layers along with polyfoam, latex, and/or minicoils/nanocoils. A mattress with memory foam/polyfoam comfort layers and a high-density foam support core is also known as an all-foam bed. Alternatively, mattresses with memory foam comfort layers and pocketed coil support cores are called memory foam hybrids. By definition, a memory foam mattress contains at least one memory foam comfort layer and a polyfoam support core.
In addition to standard memory foam, specialized memory foams are also widely used. Examples include gel memory foam, which is infused with cooling gel for temperature neutrality; other cooling infusion materials include graphite and bamboo, as well as copper (which also promotes stronger bloodflow in sleepers with poor circulation). Memory foams also vary by manufacturing process; open-cell foams are softer and more breathable, while closed-cell memory foams are firmer and less breathable.
Memory foam, like polyfoam, is measured using density. However, density ranges for memory foam differ from those of polyfoam. The table below breaks down common density ranges for memory foam comfort layers.
|Grade||Density Range (PCF)||Attributes||Average Cost|
|Low||3.9 PCF or lower||Good motion isolation and some responsiveness
Contours to some extent
Retains shape very quickly
|Medium||4.0 to 5.4 PCF||Very good motion isolation and minimal responsiveness
Contours to a noticeable extent
Retains shape somewhat slowly
|High||5.5 PCF or higher||Excellent motion isolation and very little responsiveness
Contours very closely
Retains shape very slowly
For many sleepers, medium-density memory foam offers a good balance of contouring, motion isolation, and shape retention; the price-points are middle-of-the-road, as well. Low-grade memory foam does not isolate motion as well and conforming is average at best, though the cost is usually fairly low. High-grade memory foam is considered top of the line in terms of conforming ability and motion isolation, but these qualities are often reflected in the price-point.
The softness or firmness of memory foam is also measured using indentation load deflection (ILD). To calculate ILD, set a circular metal disk with a 1-foot diameter onto a section of memory foam that is roughly four inches (4″) thick. The ILD measurement, which is expressed in numerals, will be the amount of weight (or load) needed to compress the foam by 25%. Most memory foams used in comfort layers have ILDs that fall between 10 and 20, with the ideal range for most sleepers being 13 to 15. Memory foams with an ILD lower than 10 tend to be excessively soft; likewise, foams with an ILD of 21 or higher may feel too firm for some.
Memory foam has some notable advantages and drawbacks. It is considered one of the best comfort layer materials for sleepers with chronic aches and pains. Most memory foams also isolate motion transfer very well. Off-gassing is a common disadvantage, as memory foam tends to emit more odor than other mattress materials. It may also sleep somewhat warm – though specialized and open-cell memory foams feel noticeably cooler than standard, closed-cell foams.
In terms of pricing, all-foam mattresses that exclusively feature memory foam comfort layers tend to cost less than memory foam hybrids or beds with additional comfort layer materials like latex or minicoils/nanocoils. Because memory foam is a type of polyfoam, it is considered a synthetic material. Consumers should be wary of brands advertising ‘organic’ or ‘natural’ memory foams in their beds.
Latex is a material derived from the sap of rubber trees. It has a wide range of material and industrial uses due to its natural softness and durability. The latex used in mattresses is usually processed using one of two methods. The Dunlop process yields denser latex with a more heterogeneous structure; sediment gathers on the bottom, making the material heavier. The Talalay process results in lighter, fluffier latex with a more homogeneous texture throughout.
By definition, a latex mattress contains at least one latex comfort layer – which may be Talalay or Dunlop latex – and a latex support core, which is almost always made of Dunlop latex. In most mattresses, the natural latex is blended with synthetic chemicals. Beds with small amounts of synthetic latex are often listed as ‘natural latex mattresses,’ while those that do not contain any chemicals may be certified as ‘organic mattresses’ by the U.S. Department of Agriculture. ‘Blended latex’ or ‘synthetic latex’ indicates a higher concentration of these chemicals.
Latex is not measured using density. Instead – like memory foam – the softness of latex is evaluated using indentation load deflection (ILD). The table below lists common ILD ranges for latex layers in mattresses.
|Firmness||Typical ILD Range||Latex Characteristics|
|Soft||21 or lower||The latex sinks below the sleeper’s body and conforms very closely|
|Medium Soft to Medium||22-26||The latex sinks to some extent and conforms somewhat closely|
|Medium Firm||27-31||The latex sinks to a minimal extent and conforms moderately|
|Firm||32 or higher||The latex does not sink very much (if at all) and conforms very little|
Although variations exist, the ILD for Dunlop latex is normally higher than the ILD of Talalay latex.
Latex conforms to the sleeper’s body consistently to alleviate pain and pressure points, much like memory foam, and most latex beds are virtually silent when bearing weight. Latex also carries certain advantages over memory foam. For one, latex is exceptionally durable; mattresses with latex layers have much longer-than-average expected lifespans. Latex is also more responsive than memory foam, making it better for sex; this also means that latex may not minimize motion transfer to the same extent, but most latex beds provide decent motion isolation. Off-gassing is not as much of an issue with latex mattresses, either.
A common complaint about latex mattresses is that they sleep hot. Some brands mitigate this issue by ventilating the latex layers to create stronger air circulation throughout the bed, which can help maintain a cool sleeping temperature. Many latex beds have covers made of organic cotton and other breathable materials to enhance the temperature neutrality, as well. Additionally, latex mattresses tend to be fairly expensive. This is especially true for eco-friendly beds with natural or organic latex components, as well as latex hybrids with latex comfort layers and pocketed coil support cores. By the same token, most latex pillows and latex mattress toppers are also somewhat pricey.
A growing number of beds made today feature minicoil or nanocoil comfort layers. By definition, minicoils (also known as microcoils) are usually one to four inches (1″ to 4″) thick; nanocoils are much shorter, usually no thicker than three-quarters of an inch (3/4″). Comparatively, the coils found in a bed’s support core can be up to 10 inches (10″) thick.
Because they are relatively thin and usually padded with additional comfort layers, minicoil and nanocoil layers should not cause comfort issues for sleepers. Many beds also feature pocketed coils, which are encased in cloth or fabric for added softness.
In some mattresses, the coils are zoned; this means that low-gauge (thicker) coils are located beneath the sleeper’s shoulders, midsection, and other relatively heavy areas of the body, while high-gauge (thinner) coils support the head, legs, and other lighter areas. Beds with zoned coils often offer better-than-average pain and pressure relief.
Minicoils and nanocoils may be used in beds with foam or latex support cores, but they are most commonly found in innersprings and hybrids; this is known as ‘coil-on-coil construction,’ and usually indicates stronger-than-average support. Minicoil/nanocoil layers also promote strong air circulation, which usually allows the bed to sleep fairly cool, and can also reduce motion transfer and muffle noise.
In terms of coil count, a mattress may contain up to 8,000 individual minicoils or nanocoils, as well as up to four or five individual minicoil/nanocoil and standard coil layers. Because minicoils/nanocoils are found in different mattress types, the average price-point of a mattress with these components will vary considerably. One thing to keep in mind: minicoil and nanocoil layers tend to make beds thicker, which can increase their overall profile; as a result, sleepers who prefer low-profile beds may find mattresses with these components uncomfortable.
Natural-fiber comfort layers have become more common in recent years. Often substituting for memory foam/polyfoam or latex, materials like cotton and wool offer ample cushioning, good temperature neutrality, and decent durability. Many beds with natural fiber comfort layers are also considered eco-friendly.
The table below lists some of the most common natural fibers found in comfort layers, as well as some of their notable attributes.
|Cotton/Organic Cotton||Standard cotton and organic cotton are both derived from cotton plants. Organic cotton is not grown with chemical fertilizers or pesticides.||Exceptionally soft
Breathable and temperature neutral
|Wool/Organic Wool||Wool is sheared from sheep and other mammals, then pressed into layers for mattresses. Organic wool comes from animals that are not exposed to chemicals and kept in humane conditions.||Moisture-wicking
Year-round temperature regulation
Natural fire barrier
|Silk||Silk is derived from the fibers produced by silkworms. Standalone silk comfort layers are somewhat rare; the material is often paired with wool.||Naturally soft
Year-round temperature regulation
Absorbent and durable
|Hemp||Hemp fibers are extracted from hemp plants, a form of cannabis. The fibers are durable and do not deteriorate very quickly.||Naturally dense
|Horsehair||Though rarely used, horsehair or horsetail comfort layers create a bouncy, responsive surface. These materials are usually found in luxury, high-end beds.||Exceptional durability
Good responsiveness for sex
|Coconut Coir||Coconut coir are fibers harvested from the fruit’s outer shell. The fibers are very resilient.||Exceptional durability
Good responsiveness for sex
Natural fire barrier
Lastly, it’s important to note that mattresses with ‘bamboo’ comfort layers or covers are not made using actual bamboo. Rather, the material is a synthetic fabric (usually rayon or viscose) that is derived from bamboo fibers. For this reason, bamboo is not considered a natural mattress material.
Despite the benefits listed above, beds with natural fiber comfort layers have some drawbacks. Most do not isolate motion transfer as much as foam or latex, and may result in nighttime sleep disruptions for couples. Many natural fibers also carry noticeable odors that some find unpleasant. Additionally, most mattresses with natural fibers also have expensive price-points.
In recent years, mattresses with buckling-column gel comfort layers have become popular alternatives to those with foam or latex comfort systems. Buckling-column gel was developed by brothers Tony and Terry Pearce in the 1990s. The Pearces went on to found Purple, a mattress brand that many consumers today associate with buckling-column gel.
Buckling-column gel is a dry-polymer substance derived from mineral oil that is evenly distributed across a grid or frame of rubber-like elastic polymer chambers, or columns. The columns respond to compression by sinking, or buckling; how much or little they buckle depends on the amount of weight they bear. A bed may contain up to 1,000 individual columns, each with a top, bottom, and at least one sidewall.
Buckling-column gel provides targeted support, since it sinks based on weight distribution. The material conforms to the sleeper’s body and alleviates aches and pains, and also isolates motion transfer very well. However, the elastic polymers withstand wear and tear better than most mattress foams, resulting in a longer-than-average lifespan for mattresses with buckling-column gel. The material also generates strong airflow and sleeps cool for most.
However, mattresses with buckling-column gel are very rare and shoppers face a limited selection. This means that most options carry higher-than-average price-points. Many sleepers also report a crackling sensation, especially when the mattress is new. Some adapt to this sensation over time – but others have a hard time adjusting to it. For best results, test out a buckling-column gel mattress before purchasing it.
Now that we’ve taken a closer look at the most common comfort layer materials, let’s see how they measure up to one another. The last table compares these materials based on durability, temperature neutrality, price, and other important buying factors. These ratings are generated from verified customer and owner experiences, as well as intensive product research and analysis.
|Criteria||Polyfoam||Memory Foam||Latex||Minicoils/Nanocoils||Natural Fibers||Buckling-column Gel|
|Durability||Poor||Fair to Good||Very Good||Good||Very Good||Good to Very Good|
|Conforming||Fair to Good||Very Good||Good to Very Good||Good to Very Good||Fair||Good to Very Good|
|Pain/Pressure Relief||Poor to Fair||Very Good||Good to Very Good||Good to Very Good||Poor to Fair||Good to Very Good|
|Motion Isolation||Fair to Good||Very Good||Good to Very Good||Good to Very Good||Poor to Fair||Good to Very Good|
|Noise Potential||Very Good||Very Good||Very Good||Good to Very Good||Good to Very Good||Very Good|
|Odor Potential||Poor to Fair||Poor to Fair||Good to Very Good||Very Good||Poor to Fair||Very Good|
|Temperature Neutrality||Poor to Fair||Fair to Good||Good to Very Good||Very Good||Very Good||Very Good|
|Good for Sex?||Poor to Fair||Fair to Good||Good to Very Good||Good to Very Good||Fair to Good||Good|
|Availability||Very Common||Very Common||Very Common||Common||Rare||Very Rare|
|Average Price-point||$700 to $1,000||$900 to $1,200||$1,300 to $1,900||Varies by Mattress Type||$1,500 to $2,100||$1,400 to $2,200|
Lastly, let’s look at two types of mattresses with specialized comfort layers.
Flippable mattresses are constructed with two comfort layers – one on each side – and a shared support core. Most flippable mattresses have a different firmness setting on each side; one ‘Soft’ or ‘Medium’ side and one ‘Firm’ side is a common configuration. To adjust the firmness, simply flip over the mattress. Flippable beds are ideal for sleepers whose firmness preferences vary from night to night.
Dual-firmness mattresses are one-sided models with a different firmness setting for each sleeper. These settings are intended for sleep partners whose firmness preferences are different. Most brands offering dual-firmness beds allow buyers to customize both firmness settings for optimal comfort and satisfaction.