So apparently the use 2" of memory foam on top of 2" of latex.
is that meant to be 2 " comfort layer on top of 2" of support or is that 4" of comfort layer? I know I should be asking the manufacturer but I did and they didn’t really seem to know too well.
Also have question about latex. I asked them what kind of latex they used and asked if it’s 100% natural dunlap. They said it’s all dunlap, no blends, no synthetics, and nothing but dunlap but it’s not 100% natural. Is that possible? If no synthetics, and no blends, then wouldn’t it be 100% natural dunlap then? I don’t know much about latex so I’m just asking straight up. And I think dunlap is used more for base/support foam? Or would it be considered adding to the comfort layer? Because only 2" of comfort layer seems a bit slim.
There is no strict definition of a “comfort layer” or a "support layer because which parts of a mattress primarily provide pressure relief and which parts primarily provide support can depend on the body type and sleeping positions of the person but I would call the top layer a comfort layer and the middle layer is more of a transition layer.
There is more about primary support and secondary support and their relationship to pressure relief and the main functions of different layers in a mattress in post #4 here and in post #2 here
Yes … there are many manufacturers that use 100% natural Dunlop latex in their mattresses which means that there is no synthetic rubber used in the latex formulation. While 100% of the rubber that is used may be natural, it doesn’t mean that 100% of the latex layer itself is rubber because there are other substances that are needed to foam and manufacture the latex (see post #7 here).
There is more about the different types and blends of latex in post #6 here.
All latex comes in a wide range of firmness levels so any type of latex can be used in comfort layers, transition layers, or support layers depending on the firmness of the latex and the design of the mattress.
There is more about the Sleep Science 11" Black Diamond in post #4 here and a forum search on Sleep Science Black Diamond 11 (you can just click the link) will bring up more comments as well.
There is also more about buying a mattress from Costco in post #4 here and more about the different ways to choose a mattress (local or online) and how to reduce the risks involved with each of them in post #2 here.