What is reflex foam?
If you’ve been looking at a foam mattress such as Memory foam, Eve, Casper or Simba you may have come across the term ‘support foam’. This article will help explain what support foams and reflex foams are and why they are used in foam mattresses.

What is reflex foam?
Reflex or the base foam (the part of the mattress under the memory foam) is the denser and firmer supportive part of the mattress. We use British Vita foams reflex branded foam. These come in a different density rating, usually 30kg (Soft) to 33kg (Firm). Very few manufacturers give you any detail on this part of the mattress, but we do! The British Vita foam reflex foam we use is solid filler free, unlike cheaper PU foams which are a mix of different foams.
The highlighted area in the image below is the Reflex layer of the mattress, shown as a white foam. See our data sheets for all the foams here.

A standard memory foam mattress comprises of the memory foam top layer and then either one or more layers of Memory Foam or reflex foam. The best way to imagine it, because we really like old fashioned cakes, is that memory foam is the soft icing on a fruit cake, and the reflex foam is the firm fruit cake base that supports the icing.
There may be other ‘marzipan’ layers present but the reflex foam is the base, and this offers you your support.
Foam Grade | Density Min KG/M3 | Density Max KG/M3 | Hardness Min (n) | Hardness Max (n) |
---|---|---|---|---|
Reflex 300 | 30 | 32 | 100 | 130 |
Reflex 300F | 30 | 32 | 130 | 160 |
Density and hardness are quoted according to in-house test methods based upon BS EN ISO 845 and BS EN ISO 2439 respectively.
Reflex can also be used to firm up upholstery layers such as in our Origins Pocket Reflex 1000 model. It can help provide a firmer consistent top layer when matched with softer elements such as polyester.
Mattress Support Foam
There is also another set of foams used in Mattresses and these are identified by a V rating and a number. These foams are high support foams used in seating, car seats and mattresses that must offer support for heavier sleepers such as 22-30 stone sleepers.
These V support foams are excellent at both resilience and support and can be coupled together to make a superbly comfortable yet supporting mattress for heavier sleepers or those who want an ultra firm mattress. As these V foams have such a high hardness and tolerance for resilience against heavier weights they can provide a much stronger mattress in terms of longevity. Our resilience range features V38 a firm support foam and V39 a medium support foam that can handle repeat pressure whilst still keeping its shape. For more information please see our two Resilience models made specifically for a heavier sleeper or someone wanting much more resilient support.
An example of support foams can be seen below.

Does Reflex Foam smell?
There is a smell usually present with all foam mattresses as they ‘Offgass’. This usually dissipates in a week or so but some people can be hypersensitive to the smell of new foams and mattresses. Good ventilation can help reduce it or choosing a more Natural Fibre mattress that has fewer chemical compounds to offgass within it.
Is reflex foam different from memory foam?
Yes, Reflex foam is far firmer than memory foam and is not as viscoelastic meaning it doesn’t mould as quickly to the body like memory foam. It’s still heat retentive like all foams are when compared to natural fibre upholstery. This can lead to sleepers getting far hotter than they would in asay a wool and horsehair mattress. Memory foam has an open-cell structure meaning it can trap air and heat and then mould to the sleeper. More often than not Reflex is used beneath memory foam as the support layer.

Whats a better alternative to reflex foam?
If your budget allows then a Pocket Spring unit is always preferable to a Reflex foam support layer. This is because:
- Pocket springs work independently whereas Reflex foam is one solid mass of support
- Pocket Springs are far more breathable compared to foams
- You can choose different gauges and tensions of springs based on your bodyweight whereas Reflex foam comes in only firmer tensions (It’s not suitable for lighter sleepers)
- Pocket springs don’t suffer from the compression rates that foam does and therefore have a significantly longer lifespan.

Reflex foam is the undersung hero of support in an entry-level/foam-based mattresses. Whilst there is nothing super-advanced about it, it does do a great job to provide support in a foam construction mattress. It is an entry-level priced component and will be found in entry-level mattresses. However, if you are looking for a handcrafted high-end mattress, then you should be looking for more natural advanced construction methods.



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