Thanks for the reply, Phoenix. You did indeed confuse me a bit, but that just goes with the territory. The physics of mattresses and their interactions with bodies is inherently complex.
I was curious why they (Sleepworks) use 2" comfort layers because it seems common to see 3". Many/most of the DIY vendors do this, as does Nest and Foamorder.com.
Bay Bed uses a 1" Talalay comfort layer over 6" of Dunlop, and when I asked why, they said only that theyāve found 7" of foam to be sufficient.
Iām 5ā 11", about 195 lbs (BMI 27). I sleep mostly on my stomach, but a bit on my side.
Iāve been sleeping for 18 years (!) on an Ikea single-layer all-latex mattress, which in another thread you said was probably 14 cm thick (almost certainly Dunlop). Though I probably should have replaced it at least three years ago, I think itās still safe to say I like medium to medium-firm mattresses (though I realize those terms are vague).
I ended up ordering from Foam Sweet Foam. Given my info, they recommended this (all layers 3"):
top - Medium Talalay (ILD: 27, Density: 5.0)
middle - Firm Dunlop (ILD: 32, Density: 5.3)
bottom - X-firm Dunlop (ILD: 38, Density: 5.9)
This is what I was already thinking Iād like to try, but nobody in the Bay Area has it.
After reading your post, Iām even more concerned than I already was that the Talalay comfort layer might too soft. However, FSF has a good comfort-exchange policy. One mitigating factor is that the Sleepworks had Talalay support layers, while the FSF will have Dunlop (though I seem to recall reading here that in support layers at higher densities, the difference between Talalay and Dunlop might not be very noticeable - correct?).
On their web site, FSF says āWe do not get many people exchanging layers, but when we do, they usually send back a Talalay layer saying it is too soft and too bouncy.ā They theorize that this is because theyāre accustomed to sleeping on a packed-down old mattress.
That was exactly my initial reaction to the Talalay comfort layers at Sleepworks - too soft and bouncy, both in all-latex mattresses and in hybrids.
However, I also found that what they say about people getting accustomed to packed-down old mattresses is true. When I first tried the āfirmā at Sleepworks (2" N7 Talalay over 6" N8) , I liked it and felt that the āmediumā (N6/N8) was too soft. About two weeks later, having tested other mattresses in the interim, I tried them again. While āmediumā still seemed a bit soft, the āfirmā was definitely too firm. I tried again a few days later, with the same results.
Other data points: At Foam Store of Marin, I tried these two (all layers are 3" of organic Dunlop):
āFirmā
Top: Firm - N31
Middle: X-Firm - N36
Bottom: X-Firm - N36
āMediumā
Top: Medium - N28
Middle: Firm - N31
Bottom: X-Firm - N36
āFirmā was too firm when on my side - too much pressure on my shoulder. āMediumā didnāt feel quite right on my shoulders either, but I imagined it was because I was sinking in too far. I ended up ruling these out because 1) I wanted to try Talalay on top and 2) organic latex is out of my price range.
If you have any thoughts on all of this, Iād love to hear 'em!
Bob