How do you distinguish sofa sponge between rubber sponge and recycled sponge?

How do you distinguish sofa sponge between rubber sponge and recycled sponge?

Sofa is a kind of furniture. There are sofas in the home and also in the office.How do you distinguish sofa sponge between rubber sponge and recycled sponge?
Recycled sponge is easy to see.It was made of tiny pieces of sponge.This cotton is not durable.It is out of shape if you sit for a long time.
There are various rubber sponge.Look at how it foams! The denser the sponge, the better.