What is ILD?
ILD or Indent Load Deflection, is a measurement of how “springy” a given sample of foam is. Some companies use this measurement as a way of confusing customers by saying that their memory foam has a higher ILD than their competitors.
The problem with this, is that ILD is a useless measurement when applied to memory foam. Memory foam, by definition, is supposed to conform to the body, so “springyness” is really beside the point. In fact, you can have two types of memory foam with identical density, and quality and performance, but vastly different ILD ratings. In the foam industry, ILD is used to measure conventional foam, but not visco-elastic or “memory foam”. If a salesman tries to sell you on a “high ILD memory foam” don’t let him get away with it. He’s trying to confuse you. Density is a much more useful and relevant measurement, so stick with that.