Body generates lot of humidity over night. For me personaly ventilation is most important factor rendering lot of products unacceptable.

Another mattress factory

Natural things

Some types overview, not very correct, but useful

In Australia the lowest density (weight) foam made is 15 kilograms per cubic metre and the average density of foam sold is around 19 kilograms per cubic metre. 30 years ago the average density sold was about 24 kilograms per cubic metre but as price is such an important issue in the Furniture Industry (because of competition internally and imports externally) many manufacturers are using more and more low quality foam.. This is a big pity – however a sign of the times.

Capitalism is extremely bad and inefficient thing.

In most applications as I said, 35kg/m3 minimum must be set and for mattresses it must be from 40kg/m3 up to 60kg/m3. This is real way to not produce lot of waste, contrary to idiotic claims of processing of degraded and used foam (very costly and you can do only limited thing from it, usually of low quality).

Leggett Labs

Good springs are durable