IFD (Indentation Force Deflection), also known as ILD, is the measure of the firmness of a foam. It is used in everything from memory foam to car seats. IFD/ILD measure the deflection of a foam under a load. The specific IFD test gives the foam a numeric IFD value. The higher the number, the firmer the foam. This means, for example, that memory foam will have a much lower number than a base foam for a mattress and a car seat will have a higher number than mattress base foam.
Continue reading “The IFDs/ILDs for the Healthy Foundations 10″ Memory Foam Mattress” »