Hi nhbob,

There are many reasons for this but it would probably be connected to the types of stores you are visiting and perhaps more than anything the desire for increased profit margins and the sales of less durable mattresses that need replacement more often made by major brands and sold at mass market outlets. Latex is still fairly common at smaller sleep shops and independent manufacturers who understand it’s benefits and are more focused on higher quality, better value, and more durable mattresses that don’t need to be replaced as often. It’s the same reason that two sided mattresses are so uncommon with the major manufacturers and chain stores but are so frequently seen with smaller manufacturers.

Post #4 here has several links to posts which include all the manufacturers and “better” options that are close to you that I’m aware of. Hopefully some of these will be withing reasonable driving distance. Otherwise as you mentioned … an online manufacturer or retailer would be a good option.

35 lb latex is an ILD rating rather than a density rating and latex comes in many levels of firmness. I personally believe it is “worth” the difference yes because latex is a much higher performing material and is a more elastic, adaptable, durable, and supportive material (in terms of its ability to create the best possible alignment) than polyfoam. This is also a preference though that would be connected to each person’s budget, “value equation”, which type of “feel” and response they prefer, the specific layering of the mattress, and the many other factors and tradeoffs that are involved with each person’s choices including any difference that each person can either “feel” or how well the specific mattress they are testing keeps them in alignment in all their sleeping positions (which can’t really be felt as easily but is one of the two basic functions of a mattress). In other words … whether it is “worth it” would depend on the person and the specific mattresses they are comparing.

There is more about the different types of layering here, some guidelines about height and weight here, and some guidelines about different sleeping positions here but any specific advantages or disadvantages would be specific to the person and their own needs and preferences along with all the other layers and components that are in the mattress. Getting into the “theory” of mattress construction beyond just some general information that will help you ask better questions (that may have different answers with each manufacturer depending on how them make their mattresses) and work more closely with each manufacturer or retailer is generally counterproductive and will generally lead to “paralysis by analysis” only to find there are no “formulas” that can be used to make a specific suggestion for a specific individual except based on “averages”. It’s much better and more effective to work with the experts that to try to become one or to design a mattress using “theory at a distance” IMO.

The biggest advantage of having two base layers is the ability to customize the mattress to greater degrees ( two 3" M/F layers for example would be different from either a 6" medium or a 6" firm layer) and the ability to re-arrange or exchange a 3" layers can lead a greater ability to make adjustments or changes. Of course this advantage would only be worthwhile for those who needed this greater degree of fine tuning and where any extra costs or the complexity involved over a single 6" layer were worth it for them. In spite of the amount of analysis that tends to happen on a forum like this … most people are fine with only a few choices of support layers under a few choices of comfort layers in a latex mattress which tends to produce a mattress that works very well for most people.

Those that are more sensitive or have a narrower range of pressure relief or support needs that works well for them can have a more difficult time because this degree of fine tuning may be more complex than they realize because layer thickness, layer firmness, type of latex, any other materials in the mattress, and the type of quilting and ticking materials will all interact together and without a fair bit of experience and knowledge some of the choices involved can be counter intuitive.

My motto is “find the expert” that make or sell mattresses and just gather enough information to identify them. They may all have different ideas about the type of layering that works best based on their preferences and experiences but this is because “many roads lead to Rome” with Rome being your perfect mattress.

The choice of comfort layer depends on the type of construction, the body type, and the sleeping positions of the person and there are many variables (as you can see by the links to the various sections of the site). There is no right or wrong and the only goal is to find a mattress which first meets your needs (pressure relief and alignment in all your sleeping positions) and secondarily meets your preferences (many of which are listed in post #2 here). How to get there is not nearly as important as getting there using materials that are as durable as your budget will allow. There is also no specific definition of a “comfort layer” because what you are looking for is a depth of cradle that will re-distribute pressure in all your sleeping positions and every layer will contribute t this although the top layers are more involved than the deeper ones. For example a softer middle layer can use a thinner top layer to get the same effect.

Again … everything is a tradeoff and it depends on what is more important to you and on the other layers of a mattress. For example someone who wanted more of the “feel” of an upper soft latex layer would likely choose a stretch knit cover while someone who wanted a more breathable wool quilting or wanted a split top layer that needed some quilting materials to even out the split may choose a wool quilted cover. Your own testing and preferences would be the deciding factor and since each manufacturer or retailer may have different covers … they are probably in the best position to tell you about the specific benefits and tradeoffs of each choice they offer in combination with the other layers of their mattress. Your own personal testing on each type can also give you a much better reference point than just theory. For example … the Pure Latex bliss mattresses all use softer latex in the upper layers with a stretch knit cover while the Natura latex mattresses (and others) tend to use a thicker wool quilting so depending on what types of mattresses are available for testing locally … they can give you a better sense of how each combination feels for you which can in turn be used as a guideline if you are purchasing a mattress from an online source.

I generally recommend no more than an inch or so of soft polyfoam (not any “material”) above the latex because more than this can result in the thicker polyfoam layer becoming the weak link in the mattress and it would begin to feel more like a polyfoam upper layer than a latex upper layer. Some people prefer a thin soft polyfoam quilting layer because it can lower the high resilience “feel” of latex which for some feels better than sleeping directly on latex. I would also tend to avoid thicker layers of synthetic fibers which can degrade, compress, and become firmer over time. Even thicker layers of wool will compress and firm up over time but this is part of the “normal expectation” for wool and would depend on how much wool was in the mattress. Wool is a more resilient fiber and will still have resilience even when it is compressed. Thicker layers of wool can always be added as a topper for those who want it so that the topper can be replaced if necessary. When you see for example 3" of wool in a mattress quilting you will usually find that it has been compressed to a much thinner layer than this so it can be used as a fire barrier and the 3" is only the original thickness of the “fluffy wool” before compression.

I get the sense that you may be becoming overinvolved in the analysis of mattress specs which can lead to frustration and “paralysis by analysis”. I believe you have enough of the basics that I would tend to focus on talking with manufacturers and retailers and let your body gather as much information as possible through personal testing so you have a reference point about what some of the “specs” actually feel like for you.

If there is little available for testing locally … then I would focus more on the knowledge and suggestions of any online manufacturers and retailers you are working with and let their experience and knowledge about the specific mattresses they make and sell along with their feedback from thousands of customers work to your advantage :slight_smile: