I have been reading this forum and articles at this site for a short while. It has been very helpful and most informative.
a very large thank you goes to Phoenix for its creation and moderation.
My wife and I are looking for a new mattress and have decided on latex (preferably natural) for various reasons. We prefer a layered approach with zipper cover such as 3/3/3 versus 6/2 or 3. We feel this will give us more choices for subtle changes. We have tried many mattresses to this point and we’re trying our best to let our bodies to the talking but our minds appear to want to play as well.
Thus, we are thinking about ILD’s and how various combinations can compare. This would be helpful in comparing a model seen with 6 inch layer in a mattress and trying to create a match with two put together 3 inch layers. For instance, how would two 3 inch layers of same latex compare to one 6 inch layer? Ex. two natural talalay 3 inch 32 ILD one on top of the other compare with one 6 inch 32 ILD same latex. Since the talalay are uniform this is easier to discuss than dunlop.
With dunlop, assuming you didin’t go through it, it seems to me that one 3 inch layer on the ground would feel firmer than that same 3 inch layer on top of another (same ILD) 3 inch layer. As far as dunlop is concerned I understand that it is heavier on the bottom based on how it is made. My understanding is that most or all are made as 6 inch layers which can be cut down by another party. If that is the case does that create two different 3 inch dunlop layers with different ILD’s.? Could this create what we see as med. and firm dunlop with 35 and 40+ ILD.?
If both of the 3" layers were exactly the same type and ILD of latex as the single 6" layer … most people would not notice a difference. In “theory” multiple layers “act” slightly softer than single layer of the same thickness and for example three 1" layers in the comfort layer may be noticeably softer than a single 3" layer but if the only difference was a single 6" layer vs two 3" layers in the bottom two layers in a mattress, it’s unlikely that anyone would notice any difference.
Of course if the ILD’s are different in the bottom two 3" layers then it would make a difference compared to a single layer that was all the same ILD.
Yes … a 3" layer will compress to a greater percentage of it’s total thickness with the same weight as 6" of the same material and will feel much firmer on a floor. Thicker layers act softer than thinner layers … all other things being equal. They also allow more of the layers below them to “come through”.
In effect yes. Both of them would have the same ILD rating as the original core but they would be different yes. Some manufacturers will sometimes “re-rate” a layer because of this because they don’t agree with the original rating and it seems to be firmer or softer to them. You can see an example of this in post #15 here.
Thank you for the response.
When I tried a shifman latex mattress with a 6 inch core of 32 ILD Talatech latex, 2inches of Talatech 19 ILD and 1 inch of additional polyfoam on top, the feel was significantly firmer than a zippered mattress with bottom 3 inch dunlop 40+ ILD , middle 3 inch of dunlop 31-39 ILD and top 3 inch of natural talalay 20-24 ILD. By the numbers this doesn’t make sense but other factors must be significantly involved, not just subtle differences.Can you explain?
You’re right … by the numbers this makes little sense.
One possible explanation is that there is something in the quilting of the Shifman that makes it feel firmer (lessens the amount the latex compresses). This could be a layer of fiber or it could be that the 1" polyfoam quilting is much firmer.
Another is that you are sinking through the softer 2" of 19 ILD comfort layer and the inch of presumably softer quilting foam that you are feeling more of the 32 ILD below the comfort layers while with the 24 ILD comfort layer you are more isolated from the layers below.
The third possibility is that the numbers in one or the other are wrong.
I read your reply to Nefertiti in regards to ILD. You describe what I was thinking in reference to when a 6 inch latex layer is cut into two 3 inch layers. Is this usually done by the retail seller?
Is the significant variability in dunlop latex ILD and the little change in Talatech ILD the reason why some manufacturers use Talatech? They like the uniformity intheir mattresses?
Then this could be one of the main reasons why some people are unhappy when they get their new mattress and it feels different from showroom. If they are using three 3 inch layers of dunlop with more variability in the ILD, ex. medium dunlop with ILD of 31-39 where they might get a 3 inch layer that is 32 or 38 on average, and multiply that with the variability of theother two layers one would see that the mattress might have a significant different feel. Whereas, a mattress such as PLB made with Talatech is going to have very close feel from one mattress to the next. Of course with PLB mattress you have only one settup of layers wheras with the three layer approach you could change the way the mattress feels. Which is better? What happens if you get a three layer mattress and it feels totally different than what you experienced in the showroom.
To some extent I imagine some of the variability might be muted with better retailers who take the time for good QA and what they say is soft, medium and firm is very close from layer to layer. Is this true of Savvy Rest? Do they cut the 6 inch layers themselves into 3 inch layers or are they sent to them by CoCo as 3 inch layers who then place soft, med. and firm on the layers of latex?
Does LI send out its layers as 6 inches and then cut by retailer or do they cut the latex into 3 inch layers at LI and use their QA on Talatech or natural latex layers when they are sent out?. So that, for ex. N1 - N5 would be sent out to retailer in 3 inch layers, then I would have more confidence that the QA is good.
No … this is usually done by a mattress manufacturer or by a foam fabricator, not by a retailer.
In some cases yes. There would be many reasons for different mattress manufacturers to choose one over the other and consistency could be one of them in some cases. In others … it’s not an issue and they would use Dunlop in their mattresses because they prefer its qualities over Talalay, like the greater natural latex content, have better or more economical access to Dunlop, or even have a personal preference for it. The reasons different manufacturers choose different types of material can be as individual as people.
This could be the case sometimes but in general this type of variation is not an issue for most people who wouldn’t feel the variation anyway. Most people won’t notice an ILD difference (depending on where it is in the mattress) that’s less than about 4 ILD or so. It’s not an exact science and most people pay much more attention to getting ILD right down to the last number than they really need to or would notice. Of course some people can feel finer differences that most people can’t. Differences or variations in the upper layers are more noticeable than in the deeper layers which is sometimes why you will find mattresses that use Dunlop in the deeper layers and then Talalay on top. Manufacturers will sometimes notice any significant differences as well and change the “rating” of a layer.
There really isn’t any better or worse as much as all of these are a matter of preference and part of each person’s value equation. In a 3 layer mattress with a zip cover then there are options for replacing layers or exchanging layers that a “finished” mattress doesn’t have so some people may call this “better” but this is only one of the differences between mattresses that may be more or less important to different people. latex is a very durable material whether a layer can be changed out or not and some of the finished mattresses have a design that uses different layer thicknesses and ILD’s to create different types of feel or performance which can’t really be duplicated with standardized thickness layers. It would be quite rare for a mattress that had 3 layers that were rated as S,M,F, etc to feel significantly different from a showroom for most people although of course it’s possible in which case a layer can be exchanged.
Savvy rest doesn’t cut the layers themselves as far as I know and would have either CoCo or a fabricator cut them. I think though that a lot of better retailers will accommodate exchange requests where it appears that there is some significant anomaly in the rating. I don’t know the specific policy of Savvy Rest as a company and it would probably depend on the specific outlet that was selling them. My guess is that people’s subjective perceptions between what they remember feeling in the store to what they feel in their bedroom will probably vary much more than the latex itself. This would be particularly true if people are testing mattresses more “subjectively” in a showroom and for just a few minutes instead of testing them more objectively, fully relaxed, and for longer periods of time.
That depends on each case. LI can cut them, a fabricator can cut them, or a manufacturer that has the equipment can cut them. I’m not sure what QA means but it’s always the full core that is tested and rated by LI and then every thinner layer that is cut from that core would have the same rating no matter who cuts it.