Nope, density and ILD (Indentation Load Deflection) are not the same when it comes to latex toppers or mattresses.
As I pointed out previously density refers to the mass or weight of latex material per unit volume, typically measured in pounds per cubic foot (lbs/ft³) or kilograms per cubic meter (kg/m³). It provides an indication of how much latex material is used in particular size topper or mattress.
ILD, on the other hand, measures the firmness or softness of the latex. It is a measure of how much force is required to compress a specific area of the latex. ILD is usually expressed as a numerical value, such as 14ILD (soft) and 44ILD (very firm) and a higher ILD indicates a firmer latex, while a lower ILD indicates a softer latex.
The bottom line is, density is a measure of the amount of material in the latex, while ILD is a measure of the firmness or feel of the latex. Some manufacturers often provide both density and ILD information to help folks choose a latex topper or mattress that meets their preferences for both support and comfort.
It can be a tad confusing, but if we consider or look at the analogy of baking a cake. If you take a 1lb cake and compress it from a height of 4" to 3" while keeping the weight constant, the density increases as the material becomes more compact. On the other hand, if you incorporate air into the cake mix, creating a fluffier and airier batter with the same pound of ingredients, you get a less dense and loftier cake. Both cakes have the same weight but provide distinct textural experiences. This principle also applies to volume – compressing the batter in a square cube pan until it cannot take any more compared to loosely pouring a more airy batter into the same volume results in a lighter cake.
Hope this clears it up without confusing the issue. I have to re read what I write to be certain I understand myself sometimes. LOL
Maverick