There are many properties of foam. The two most important are: Density and ILD.
Density is nothing more than how much a piece of foam weighs. It is determined by taking a cubic foot of foam (12" x 12" x 12") and weighing it. If the foam cube weighs 5 pounds, the density is 5.0. If it weighs 2.5 pounds, the density is 2.5. The higher the density, the longer the foam should last. The best foams for extended use are ones with a density of 1.8 or higher. Foams with a density of less than 1.8 are adequate for temporary use.
ILD stands for Indentation Load Deflection and refers to the firmness of a piece of foam. The lab puts a 4" x 15" x 15" piece of foam on a flat surface. Then a round metal plate, 8" in diameter, pushes down on that piece of foam. The amount of pounds of pressure it takes to squeeze the 4" piece of foam to 3 inches (25% compression) is referred to as the ILD. A low ILD, such as 10, doesn't offer much resistance and is an extremely soft piece of foam. A piece of foam that takes 46 pounds of pressure is an extra firm piece of foam. Generally speaking, ILD's of 10-22 are considered soft, 23-29 are medium, 30-37 are firm, and 38+ are considered extra firm. The comfort range for most people is 25-35. Foam does soften slightly with regular use.
Polyurethane foam and Latex foam are the two foam types used primarily in the bedding and cushioning industries.
Polyurethane Foam
Polyurethane foam is widely used in the furniture and RV industries for cushions and bedding. It is a cost effective alternative to latex, but is not natural and will not last as long.
Latex is derived from the rubber tree. It is a natural, biodegradable material that is inherently anti-microbial, anti-bacterial, and dust mite free. Latex inhibits the growth of mold, mildew, fungus, and bacteria. This makes it the best option for health conscious consumers and those who suffer from allergies. We have not seen a foam product that comes close to the quality and resilience of Latex.
It starts as a milky white liquid composed of rubber, dispersed in water. This material is whipped with air to form a foam, which is frozen in place to make the Latex core.
The Latex core has a pincore construction with hundreds of tiny air channels. Because of this natural ventilation, it provides more breathability, keeping you warmer in the winter and cooler in the summer. The density of the Latex core is approximately 5.0 pounds per cubic foot. This is twice the density of the best high resilient polyurethane foam. More weight means longer life. It is available in Soft, Medium, Firm, and Extra Firm. There is no resilience like Latex. If you have slept a night on it, you know.
The two main types of Latex are Talalay and Dunlop. These names refer to the manufacturing process in which they are made. The liquid latex that goes into each can be 100% natural or a blended mix. That gives you 4 choices: 100% Natural Talalay Latex, 100% Natural Dunlop Latex, Blended Talalay Latex, and Blended Dunlop Latex.
Talalay - is a very sophisticated manufacturing process and the more popular of the two (see the video below). Talalay latex is very resilient, very cushy, and very comfortable. Because of customer demand, we sell only the 100% Natural Talalay Latex
Dunlop - is less sophisticated. The 100% Natural Dunlop will not be as resilient and will feel a little bit stiffer and firmer, but is a good product. The Dunlop blend feels very dead and should only be used for the bottom layer of support, if at all.