Im 6’4, 200lbs and sleep on my side 99% of the time. Thanks to your site, Ive done my research and discovered Im interested in latex mattresses with 6" cores and 3" support layers. I’ve had the chance to try a bed with a medium/firm Dunlop core and medium Talalay support which I liked pretty well. I am looking online and see a mattress with a blended Talalay core and support at a very competitive price.
I saw in one of your posts that Talalay cores will feel more ‘springy’ than the Dunlop:
If I were to buy this one online, should I get a ‘firm’ core to compensate for the difference between the 2 materials or would you say that they are more or less the same?
Am I right in thinking that a Talalay core with ILD 36 would be more or less the same as a Dunlop core of ILD 32?
Many manufacturers of 100% natural Dunlop don’t rate their cores in terms of ILD and density may be the best way to compare them. There is more about the difficulties of using ILD as a comparison in post #6 here but in many cases it’s not reliable unless the listed ILD is accurate and you are comparing the same type of material (Dunlop or Talalay and 100% natural or blended).
ILD comparisons between Talalay will generally be more accurate than ILD comparisons between Dunlop or between Dunlop and Talalay.
Post #2 here has more about how to make the most suitable choice in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) but it boils down to using either your own personal testing and experience or having a more detailed conversation with a manufacturer or retailer on the phone that has the experience and knowledge to provide you with some guidance based on “averages” for their mattresses and other customers that are similar to you.
This is a much more complex question than you may imagine and there are many “it depends” in the answer. They will also “feel” different.
If the Dunlop and Talalay were both the same thickness and both had exactly the same ILD that used the same method of ILD testing and the core was compressed exactly 25% then they would be the same. How much each support layer is compressed though depends on the weight of the part of the body that is above it and on the thickness and softness of the layers above it as well. If Dunlop is compressed less than 25% under a certain part of the body it will generally be softer and if it is compressed more than 25% under a certain part of the body it will be firmer than the same ILD of Talalay because it has a higher compression modulus and gets firmer faster as it is compressed more deeply. It has a different response curve in other words.
In a comfort layer Dunlop of the same ILD as Talalay will generally feel firmer (assuming the ILD is accurate in both) because comfort layers are generally compressed more than 25% of their thickness so in this case your estimate would be reasonable. In a support layer it would depend much more on your body weight and weight distribution, the thickness/softness of the comfort layers, and on the type of cover as well so it’s not really possible to know for certain outside of your own experience and perceptions (although it’s probably accurate to say that if the ILD of the Dunlop was accurate it would probably feel “somewhat” firmer than the same ILD of Talalay in many constructions)
If you have a specific model that you have tested and works very well for you in terms of PPP then I would stick as close as possible to what you have tested with an online purchase because every change in the design, materials, or components of a mattress will have an effect on how the mattress feels and performs for you.
One last question (for now). Would you consider a blended 6" Talalay core ILD 32 and 3" support ILD 19 to be within ‘normal’ ranges for a side sleeper? I have the option to choose from either 19 or 28, but was told if 19 was too soft I could pull it out and swap positions with the core layer to give a bit more firmness. Is that true/advisable?
For lower to average body types I think it would be inside the averages that would work for many people yes.
It would probably be on the firm side for most people if the 32 ILD layer was on top and those who like a firmer than average sleeping surface may prefer the 28 ILD comfort layer compared to the 19 ILD.
The cover will also make a difference in the feel and performance of the mattress not just the latex layers.