|Don's Home Home - Garden Foam Rubber|
Some general information on foam rubber I found when researching mattresses.
Latex: (natural rubber)Open-cell sponge rubber - air or gas can pass through them similar to the way water is absorbed by a dish sponge.
Closed Cell sponge (expanded rubber) Floats, Functions well as a shock absorbing material.
Products — Bergad Specialty Foams & Composites offers,