The Marriott Bed has become synonymous with luxury - and is recognised as one of the plus points of the international hotel chain. A widespread overhaul of the beds at the hotels and resorts in the last couple of years which saw the introduction of mattress toppers has strengthened this claim further, and it’s because of this popular appeal that the beds are now available for public sale, giving everyone the chance to experience the same luxury at home.

We trialled the King Size over a period of two days, here’s what we found.

The Marriott bed is a traditional pocket-sprung mattress with a topper. The topper doesn’t use memory foam, but synthetic fibre balls (a natural alternative is also available). The topper gives the bed a particularly soft and spongy feel, which on first impressions is extremely comfortable. However, this volumous nature means that the bed lacks overall support, without the ‘rebound’ effect that good quality memory foam offers. The overall effect of this proved to be a reasonably comfortable sleep, but there was a distinct absence of feeling rejuvenated in the morning.

The plush ’sinking feeling’ of a soft mattress can be perfect for some, but naturally won’t offer anything to those used to a firmer bed.

Despite Marriott’s high-end standing in the hospitality industry, the Marriott bed appears to be relatively reasonably priced - the King Size comes in at a shade under £1700, including  the topper. However, when we attempted to uncover an itemised breakdown of the prices (mattress, base etc) we were met with the company’s automated response system, which was less than helpful.

Pros:

* Extremely comfortable

* First-class build quality

Cons:

* Will be too soft for some

* Minimal support

Memory Foam Buyers Guide Rating

Marriott Bed - King Size with Synthetic Topper - around £1700

Memory Foam (Topper) Performance - 3/5

Value for Money - 4/5

Overall - 3.5/5

Verdict: A supremely comfortable combination of pocket-sprung base and fibre topper, and a good choice for those looking for a soft option. Whether you’ll want to go for the Marriott brand coloured bed linen is another question…

The Hedfors is part of Ikea’s flagship Sultan mattress range. While the Hedfors itself isn’t a memory foam mattress, it does have an element of dual-layered foam content. This means that in effect the mattress has a built-in foam topper, on top of its conventional pocket sprung base.

We trialled the double-sized (160cm x 200cm) Sultan Hedfors, which retails at £190.

Our initial thoughts were that the mattress was slightly on the thin side, and extremely firm. Body contouring, despite the foam element, didn’t feel anywhere near as encompassing as that of a full memory foam mattress. Although what the Hedfors lacked in contouring, it made up for in general support, which proved to be very good. Consecutive nights on the Hedfors resulted in a suitably restful sleep, with the mattress firmness becoming something of an acquired taste.

This is a solid performer, let down only by its minimal use of foam. The double-layered foam content sadly gives a poor impression of a memory foam topper, and as a whole it doesn’t compare favourably with full memory foam alternatives whatsoever. However, in its capacity as a pocket-sprung mattress designed to be used with slatted bed bases, the Hedfors performs admirably.

A significant plus point for the Hedfors is that it is backed by Ikea’s excellent 25-year warranty, which protects against any manufacturer problems. In addition to this, the whole of the Sultan mattress range is covered by the “Love It or Exchange It” scheme, which allows for a 90-day trial period.

Pros:

* Excellent warranty, among the best in the business

* Good air circulation

Cons:

* Poor memory foam performance

* Non-standard sizing, requires an Ikea bed frame

Memory Foam Mattress Buyers Guide Rating:

Ikea Sultan Hedfors - 160cm x 200cm - £190

Memory Foam Performance - 1/5

Value for Money - 3/5

Overall - 2/5

Verdict: An unspectacular but reliable pocket-sprung mattress with minimal memory foam benefits, however, those looking for a firm and airy mattress may find a suitable match with the Sultan Hedfors.

It is a long-held belief that firm mattresses are ‘good’ for backs and sufferers of back pain, however, research on the issue tells a different story.

A Spanish study carried out in 2003*, the results of which were published in The Lancet medical journal, found that ‘medium-firm’ mattresses proved to be the best option for those complaining of back pains. The test involved 300 patients sleeping on ‘firm’ and ‘medium-firm’ mattresses for a period of three months. After the trial period, the participants were asked to rate their mattresses on the pain they experienced while lying in the bed, getting up in the morning and overall. The ‘medium-firm’ mattresses rated highest on all three counts. In the write-up of the study, researchers commented; “The medium-firm mattress was associated with an improvement in disability related to low(er) back pain.” In addition to these comments, the researchers praised the theraputic effects of the mattress in comparison to medical interventions on the problem, claiming; “This effect is particularly important since, although some interventions slightly improve the level of disability, very few medical or physical interventions have achieved this objective.”

Unfortunately, there’s no shortage of people suffering with their backs. Back pains and related complaints are among the most commonly reported reasons for visiting a GP, and it is thought that around 40% of the UK’s adults has experienced it to some degree. The overall problem is estimated to cost up to 11m sick days per year in Britain.

* http://news.bbc.co.uk

Ikea’s all-encompassing domination of the home furnishings market makes the Swedish giant an obvious choice to offer memory foam products, and now they have a selection of mattresses, mattress toppers and pillows that employ the hi-tech materials in some form. The Ikea memory foam pillow range consists of the Gosa Fast (firm), Gosa Mjuk (soft) and the Gosa Form (ergonomically shaped). We trialled the Gosa Fast over a week-long period, here’s what we found.

At just under £12 the first impression was naturally that the Gosa Fast was incredibly inexpensive, as little as a tenth of some direct alternatives - would this be an indication of its lesser quality, or merely Ikea’s ability to offer low prices with their bulk buying power? Time would tell.

The Gosa Fast, exactly the same as the softer Gosa Mjuk version, has a contoured shape to deliver good neck and head support. However, at just 33cm x 50cm it is very small, and doesn’t come anywhere near filling a standard-sized pillowcase. The pillow is also very shallow, which raised questions about how effective it could be in practice. The memory foam quality is initially responsive to the touch, but looking inside the covering reveals a single piece of foam with no layering.

The first night using the Gosa Fast proved to be uncomfortable, with the pillow’s extreme firmness preventing any real responsive contouring from the memory foam. The minimal depth of the pillow lowered the head and neck to almost mattress level, with absolutely no feeling of support. Despite the initial night of discomfort, later nights during the trial were marginally more comfortable but the Gosa Fast never led to a feeling of being refreshed when you wake up, which should really be a standard requirement of any good quality memory foam pillow or mattress. On some mornings, the Gosa Fast produced a sensation of just finishing a workout upon waking up, tensing neck and shoulder muscles into knots - hardly a desirable effect from any pillow, not least a memory foam.

With such ineffective and occassionally detrimental performance, the £12 spent on the Gosa Fast goes from a bargain to money wasted as long-term use is out of the question. Whether Ikea’s softer Gosa Mjuk (£12) or premium level Gosa Form (£36) could offer a better experience remains to be seen.

Pros:

* Low price

* Could suit those looking for an extremely firm pillow

Cons:

* Small and shallow

* Overly firm, leading to minimal benefits from memory foam

Memory Foam Mattress Buyers Guide Rating

Ikea Gosa Fast Pillow: £11.99

Memory Foam Performance: 2/5

Value for Money: 3/5

Overall: 2.5/5

Verdict: A potentially bargain low price option, irretrievably let down by ineffective memory foam and diminutive dimensions.

US health magazine Prevention recently ran an article highlighting the top 5 household culprits for causing back problems. What came in second place? Saggy mattresses and pillows that don’t give the body the support it needs during sleep. And what was Prevention’s recommendation? Visco elastic memory foam.

 “Your saggy mattress and pillows are putting an unfair amount of stress on your back,” said Prevention. “We spend one third of our lives in bed. Do you wake up stiff every day? A mattress that is too soft will force muscles to work overtime while you’re sleeping. A mattress that is too firm won’t support your entire spine. A pillow (or stack of pillows) that’s too high or too flat leaves your neck at an awkward angle. The wrong mattress doesn’t give you the support you need to relax… …purchase a memory foam pillow that is contoured to support your neck.”

 When respected health and wellbeing magazine Prevention (slogan - “Smart ways to live well”) is advising a visco elastic memory foam solution, it is proof of the technology’s theraputic qualities.

See the article - click here

We recently received the following comment from a consumer who was dissappointed with the performance of their memory foam mattress, reporting unacceptable problems such as dampness and even mould growth.

A new product offering to the market, Ergo Flex claims that its memory foam mattresses offer the same levels of performance as the market leading alternatives at a fraction of the price. To put these claims to the test, we trialled the Ergo Flex Double over a three-night period. On receipt of the Ergo Flex Double - which arrived on next day delivery – we were surprised to find it delivered in such a compact vacuum-wrapped package. However on opening, the Ergo Flex unfurled to its full-size and took shape, revealing a satisfying quality of memory foam. Early impressions in terms of weight, feel and standard certainly put the Ergo Flex in the same class as memory foam mattresses at the upper-end of the market. 

These impressions were backed up by the memory foam performance during the first night of the test. Support and body-forming qualities were first-rate, giving a highly comfortable, disturbance-free sleep. The depth of the memory foam’s shaping gave full support without making it difficult to turn over during the night, a finely balanced benefit in memory foam mattresses. 

On the Ergo Flex website the manufacturer explains at length the benefits of the integrated ‘cool sleep system’, which has been designed to alleviate the memory foam tendency to overheat during the night. We found this to be the case, experiencing a comfortable night without getting too warm. 

Coming in at a price point roughly half that of its genuine competitor makes the Ergo Flex a great choice, whether you’re a buyer on a budget or someone just looking for a premium memory foam mattress without paying top dollar. While label-conscious consumers might not wish to stray from the established brands, those who take the chance on a newcomer with Ergo Flex will be getting both value-for-money and 1^st class memory foam quality.  

Pros: 

• Incredible value for money
• High quality memory foam performance
• Next-day delivery

 Cons: 

• No single or super-king size options **UPDATE** Ergo Flex now has 5 mattress sizes: single, double, king, super king and euro king.

Memory Foam Mattress Buyers Guide Rating

 Ergo Flex Double (Standard UK Double) – : £699 

Memory Foam Performance: 4/5

Value for Money: 5/5

Overall: 5/5

 Verdict: Memory Foam Mattress Buyers Guide Recommended ***** - A premium quality memory foam mattress without the premium price.

Tempur is recognised as the market leader for memory foam mattresses, with an unrivalled heritage and reputation in the industry. We tested the Tempur Combi to find out if the kudus of the brand could live up to the price tag, and whether Tempur still remains the best choice of memory foam mattress today. 

First impressions of the Tempur Combi were that it was a clearly well-made memory foam mattress, with a pleasing weight and depth.  Following a night’s trial, an initial observation of the Tempur was that it was noticeably warmer than a standard mattress, to an uncomfortable level. As this is something that the company claims has been factored into the design, we found this both surprising and disappointing. The memory foam on the Tempur, while providing adequate support where necessary, has a tendency to create ‘wells’ based on your body weight – which make rolling over a difficult and somewhat exerting process. A night with three or four adjustments in sleeping position feels less like relaxation and more like a full-body work-out – not what we were expecting. Using the Tempur after a period on either a standard sprung mattress or an alternative memory foam mattress takes time to adjust, so there are no immediate benefits to be had. Despite this, the memory foam performs its body-shaping support as required, and will offer good relief for those with back pains and muscle complaints. 

Although the time-constraints of our test couldn’t assess the long-term performance, Tempur’s 15-year guarantee suggest that the mattress will retain its memory foam qualities over time, and offer reassurance for prospective buyers. 

Pros: 

• 15-year guarantee
• Quality memory foam
• Supporting, body-shaping

 Cons: 

• Hot
• Expensive
• Uncomfortable to turn over
• Difficult to adapt from a standard mattress

Memory Foam Mattress Buyers Guide Rating

 Tempur Combi (Standard UK Double) – RRP: £1199 

Memory Foam Performance: 3.5/5

Value for Money: 2/5

Overall: 3/5

 Verdict: A solid performer, but not without some disappointing downsides and that all-important hefty price-tag

Viscoelastic foam, also known as memory foam or temper foam, was first commercialised during the mid 60’s as a result of NASA’s AMES Research technology transfer program. This open-cell variety of flexible polyurethane foam (FPF) was distinguished by properties allowing it to redistribute the G-Force suffered by astronauts during take-off and re-entry, and providing commercial pilots a more comfortable seating surface during long flights. Although viscoelastic memory foam production technology has been available for more than 35 years, commercial products have only recently been made widely available to consumers. Viscoelastic pressure distribution performance represents one of the most significant comfort innovations from the FPF industry.

Memory Foam Characteristics

Viscoelastic memory foam is typified by its slow recovery after compression. When a weighted object (for example, the human body) is positioned on a viscoelastic memory foam mattress, the foam progressively conforms to the shape of the object, and after the weight is removed, the foam slowly reassumes its initial shape. Due to this gradual recovery, viscoelastic memory foam also can be described as “slow recovery” foam.

Other characteristics include viscoelastic memory foam’s ability to dampen vibration as well as absorb shock. This latter performance characteristic is confirmed in the laboratory using ball rebound tests. Ball rebound of less than 20% (compared to 50% – 60% with other varieties of FPF) supports the description of viscoelastic polyurethane foam as “dead” or “low-resilience” foam, in that it lacks the surface “springiness” of other FPF products. In fact, certain viscoelastic memory foam products claim to absorb up to 90% of impact. While lack of resilience may appear to be a disadvantage, as discussed later, a “dead” foam can be highly desirable in some applications. In addition to these key advantages, many viscoelastic memory foam products also react to body temperature and ambient temperatures, softening with heat and more easily adjusting to body contours.

Benefits & Applications of Memory Foam

Viscoelastic memory foam’s unique physical characteristics have led to its popularity in the bedding and medical industries. Due to its conforming aspect, viscoelastic memory foam material makes for a comfortable yet supportive mattress or mattress pad, and its low resilience works well in bed pillows.

People with impaired mobility, confined to wheelchairs or hospital beds (especially burn victims) can benefit from the memory foam mattress’ capacity to redistribute weight and surface pressure, potentially reducing decubitus ulcers (bed sores) caused by aggravated pressure between the skin and bony areas of the body such as beneath heels, hips, elbows and the back of the head. If pressure is not relieved through body movement or technology, such as a viscoelastic memory foam mattress surface, blood vessels may compress, inhibiting circulation and possibly irritating the skin tissue. Aside from bedding and medical purposes, viscoelastic memory foam material can be used in standard household furniture (stationary or motion), office furniture, and in some vehicle seating applications. It can cushion sports equipment, power tools, and footwear. Viscoelastic memory foam has also found utility in ergonomic applications such as neck, back and leg pads, as well as in arm and wrist rests for computers. It can act as shock protection within electronics equipment and has been used in specialty packaging, military and commercial aircraft seating, and weaponry (for recoil suppression).

Why isn’t Memory Foam used in more cushioning applications

With such valuable attributes, it would seem that viscoelastic memory foam products should be found in many more comfort cushioning applications. Unfortunately, production economics often restrict end-use applications. Unlike traditional foam processing, viscoelastic memory foam formulation flexibility is more restrictive. Raw materials must be carefully altered to generate foam with varying properties. Cutting, profiling and other fabrication techniques may also require more care due to the slow recovery aspect of the memory foam. These considerations certainly affect product economics.

Memory Foam Production Formulating and Processing

While formulating and processing can be challenging, memory foam manufacturers and chemical suppliers have worked together to develop a range of successful viscoelastic products. For instance, certain formulations can alter the memory foam’s recovery, elasticity, and firmness, giving it the ability to meet a diverse set of end-use needs. Because viscoelastic memory foam is hypersensitive to formulation, the challenge focuses on maintaining product performance consistency. This requires a close working relationship between FPF manufacturers and their raw materials suppliers. With careful attention to quality control procedures, end products can meet or exceed application performance requirements.

Physical Properties of Memory Foam Density

As with all FPF, the density for viscoelastic memory foam is the weight of one cubic foot of material measured in pounds. With conventional FPF formulations, a higher memory foam density generally equates to increased foam durability (retention of performance properties). The same is true of viscoelastic memory foam products. Density enhances durability and the ability of viscoelastic memory foam to maintain its physical performance. Viscoelastic memory foam found in most household and healthcare product applications typically ranges in density from 2 to 6 pounds per cubic foot (pcf).

Firmness

Normally, firmnesses of viscoelastic memory foams can range from supersoft (less than 10 lbs. @ 25% IFD) to semi-rigid (as high as 120 lbs. @ 25% IFD). The potential for surface pressure reduction is closely associated with firmness, and can vary based on the formulation. Viscoelastic memory foam products with a lower IFD tend to exhibit increased conformance and can distribute body weight more efficiently to alleviate pressure. However, if the IFD is very low, and there is not sufficient foam density or thickness to provide support, the product may “bottom out,” negating the benefits of pressure reduction. When performing IFD tests, firmness measurements of viscoelastic memory foam mattresses can be significantly affected by some of the foam’s key characteristics: rate sensitivity (the foam’s rate of recovery after compression), sensitivity to temperature, and sensitivity to humidity. Sample conditioning prior to testing is extremely important.

Rate Sensitivity

Viscoelastic memory foam rate sensitivity, observed as the speed that a foam sample recovers after compression, affects the way firmness (IFD) can be determined in laboratory tests. Because of rate sensitivity, when testing viscoelastic memory foam under load, as in IFD measurement, the speed at which the weight force is applied can alter firmness readings. In other words, if the indentation plate used in the test descends quickly, the memory foam mattress may respond with stiffness, whereas slower speeds may result in different IFD measurements. With viscoelastic memory foam products, IFD tests should show notation of the process speed (rate of deflection) being used so that valid and fair comparisons among foam grades and between laboratories can be consistently made.

Sensitivity to Temperature

The physical properties of viscoelastic memory foam can be greatly influenced by temperature. Even slight changes in room temperature can affect measured firmness and recovery rates. Recovery rate has been positively correlated to heat, so that as the foam increases in temperature, pliability and compression and recovery rates increase. In colder conditions, viscoelastic memory foam products tend to become firmer or even stiff.

Depending on the formulation, some viscoelastic memory foam products can maintain their “memory” feature at as low as 30° F, but the optimum range for best “memory” action is typically between 55° F and 85° F. Research is ongoing to find ways to moderate pliability and allow viscoelastic memory foam products to perform within a broader spectrum of temperatures, especially below freezing. This is especially important in vehicle seating and other applications where ambient temperature cannot be controlled in use. In testing viscoelastic memory foam performance characteristics, it is also important to make notation of the ambient temperature and be certain that all comparison testing be performed under like conditions. Sample must be conditioned prior to testing. Heat (even body heat) can soften viscoelastic memory foam materials and, in extreme situations, affect the foam’s ability to provide support. This process is known as a phase change or relaxation.

Rather than broadening the temperature range at which viscoelastic memory foam retains its slow recovery, foam formulation can be adjusted to narrow the temperature span at which phase change occurs, anticipating the influence of room temperature combined with body temperature. In other words, if the phase change occurs at lower temperatures, its reaction to added body heat could lessen its firmness to the point where support is lost. On the other hand, if the phase relaxation were to happen in warmer conditions, added body heat would not be enough to soften the foam, and the resulting foam rigidity would reduce the potential for pressure relief. Hence, careful control of the phase change characteristics is crucial for the foam to serve its pressure reduction purpose and to provide predictable support.

Sensitivity to Humidity

Not only does viscoelastic foam react to temperature but also to humidity. Viscoelastic products tend to soften in more humid conditions. For example, very pliant foam may feel slick or “buttery” as opposed to coarse, depending on the humidity. Surface feel is generally not a critical factor in end-use applications, because in almost all cases, the foam is enclosed inside a covering material that provides its own surface feel. Firmness that changes with ambient conditions can make accurate calculation of physical properties difficult.

Memory Foam Performance Testing Pressure Reduction and Pressure Relief

Because viscoelastic memory foam can closely conform to the shape of the human body, it can efficiently distribute pressure over the whole surface. Pressure-mapping equipment is often used to calculate the degree of weight distribution. During the mapping procedure, computer programs monitor pressure. The body’s impression is graphed to show which areas endure the most pressure (namely the shoulder blades, posterior region, head, heels, calves, and elbows). Some viscoelastic memory foam producers perform these tests as an indication of how well the foam might act to minimize pressure. In the healthcare area, to be labeled as providing “pressure relief,” readings must be at 32mmHg or lower, whereas “pressure reduction” performance is agreed to occur between 32mmHg and 50mmHg. The adjacent charts help illustrate the process and show some typical pressure readings for viscoelastic memory foam. When readings made on viscoelastic products are compared to those of conventional foam and other common cushioning surfaces, the pressure differences are notable.

Resolving Testing Procedures

With the unique nature of viscoelastic memory foam performance, some traditional FPF test methods do not produce consistent results. For example, measuring durability with the use of a Dynamic Pounding Fatigue Test procedure can be problematic. Due to the foam’s slow recovery characteristic, pounding fatigue data loses validity because the foam has not fully recovered in between each cycle. Compression set testing may provide a better measurement of viscoelastic memory foam durability. The foam industry uses IFD measurements to quantify FPF firmness. Unfortunately, IFD testing may not accurately evaluate viscoelastic memory foam firmness because the foam relaxes during the one-minute hold period before taking the IFD reading. Due to rate sensitivity and other factors, standard IFD testing procedures used throughout the industry are not completely understood and may not accurately measure the firmness characteristics of viscoelastic memory foam products. Recognising both the demand for consistent measurement of viscoelastic memory foam product performance properties and the importance of resolving standardized testing concerns, Polyurethane Foam Association members formed a technical task group to consider these issues. Problematic testing issues have been identified, and, through experimental testing and group testing verification, new test standards may be developed for use with viscoelastic memory foam products.

Environmental Considerations

As with any product, off-gassing naturally occurs. The formulation technologies used to produce viscoelastic memory foam products sometimes create the potential for more noticeable aromatic emissions than typically found in conventionally manufactured foam products. While not harmful, residual odour may be bothersome to some consumers. Therefore, it is advisable to thoroughly ventilate viscoelastic memory foam products prior to final product assembly. In terms of environmental manufacturing objectives and recyclability, the production of viscoelastic memory foam is a friendly addition to a very environmentally conscious industry.

Flammability Considerations

Viscoelastic memory foam can be manufactured to perform with varying degrees of ignition and combustion resistance. Typically, with the addition of flame retardants, viscoelastic memory foam products can be produced to satisfy small open flame tests such as Calif. TB117 and FMVSS 302 and can be combined with barrier materials in mattresses designed to comply with other composite-type flammability specifications. As is the case with all flexible polyurethane foams, great care should be taken to avoid contacting a viscoelastic memory foam product with an ignition source such as a lit match or candle, heating element, sparks, exposed electrical wires, an exposed light bulb or smoking materials. Once ignited, all flexible polyurethane foams have the potential to burn vigorously, emitting great heat and dense smoke.

Memory Foam Summary

Viscoelastic memory foam technology represents new and exciting developments for the FPF industry. It is taking hold in a variety of markets (from medical to bedding to technical applications and more) and offers a unique cushioning alternative to conventional and HR flexible polyurethane foams. Its performance in specialized end-use applications has been well received by consumers. Ongoing industry and individual efforts are focused on improving the control of viscoelastic memory foam’s performance, so that more successful applications can be developed for this unique cushioning, pressure distribution and shock absorbing material.

1. Viscoelastic memory foam is a type of open cell, flexible polyurethane foam.

2. Surface comfort and pressure distribution are closely related to the foam’s ability to conform to body shape.

3. Slow recovery adds comfort characteristics, but also complicates the testing of viscoelastic products.

4. Viscoelastic memory foam firmness, support and height recovery rate are often affected by temperature and humidity.

5. Comparative laboratory testing must match ambient testing conditions for accurate comparisons and replicability of test results.

6. Some standardized FPF performance testing procedures may require special considerations to accommodate viscoelastic’s slow recovery rate.

7. Viscoelastic memory foam products should be thoroughly ventilated after production and during fabrication to reduce the possibility of bothersome aromatic emissions.

8. Viscoelastic performance is a matter of taste. Some like it fast and some like it slow.

Technorati Profile

Along with density, firmness is one of the most important factors in choosing a new memory foam mattress. However, many consumers are misled by various claims of firmness based on ILD (indentation force deflection) ratings. Our handy guide to the firmness of memory foam mattresses shows how it is the combination of ILD rating, density and composition of a mattress that contributes to its firmness. 

Comparing Mattress Firmness Ratings

 An ILD rating does not give a comprehensive guide to the firmness of a mattress on its own, for the following reasons; 

• ILD ratings tell you how firm the visco elastic foam layer is, not any of the other layers used in the composition of the mattress. The core of the mattress is a key factor in determining firmness, and this is not defined by the ILD rating.
• ILD ratings could only be used to compare firmness if every other single aspect of the mattress composition was identical – size, structure, quality, material – and this is virtually impossible.
• ILD ratings do not equate to comfort, and shouldn’t be seen as the definitive factor in a mattress.

 What benefits can the ILD rating offer? 

• ILD ratings, when considered along with the other layers of a mattress, do contribute to the firmness level.
• ILD ratings can hint at the quality of a memory foam mattress. While it may be impossible to differentiate between mattresses with ratings of 13 ILD and 14 ILD, it is clear that both of these would be superior to one that had an 8 ILD rating.

 Ultimately, it is important to consider ILD ratings and density as different aspects to a memory foam mattress. The ideal composition of memory comfort layer, that we would recommend, would be; 

• 4-6lb density visco elastic foam
• 13-15 ILD rating
• 3” – 5” thickness
• Body temperature sensitive

How does mattress firmness work?

A common misconception regarding memory foam mattresses is that density is what makes a visco elastic mattress soft or firm. You may have very soft or very firm visco elastic foam, which makes using it as an index very unreliable.