Closed cell foam is used to produce mats that can be used without requiring any inflation.
Alternatively large open cell foam or plastic fibres will do.
This applies to open cell foams where the bending moment is exerted on the cell walls.
A koozie can be made from many materials like neoprene, polyester or open cell foam.
Open cell foams feel soft and allow air to flow through so they are comfortable when used in seat cushions or mattresses.
Closed cell rigid foams are used as thermal insulation, for example in refrigerators.
For weapons over 24 ounces in weight the padding requirement typically is increased to about one and one half inch of closed cell foam.
Open cell foams provide a better economical yield.
It is also available as a crosslinked closed cell foam, used increasingly in aviation and aerospace applications.
This is accomplished through the use of closed cell foam, or other non-permeable material.