These pads are made with a unique high pressure nitrogen gas solution process. High quality extrusions and cross-linking of solid polymeric sheets are impregnated with pure nitrogen gas at elevated temperature and extremely high pressure. Then the impregnated solid sheets are expanded in a huge low pressure autoclave. This process results in an extremely regular and uniform cell structure in the foam.
What this means to you is the foam is amazingly light and strong for its density. The pads are tough, flexible and resilient, and exhibit good UV stability. As a closed-cell foam, they will not absorb water.
We have the foam cut into an "egg crate" pattern for comfort. The base is 1/4", and the convoluted portion rises a maximum of an additional 1/2" above the base, for a total pad thickness of 3/4" maximum. Since the foam protrusions are solid foam instead of formed, they 'bounce back' pretty well, though they will compress with time and use. The torso pads are precisely scored, so the pads will fold in thirds to create an 18" x 10.75" x 2.25" package that fits nicely into the back of a Gossamer Gear Mariposa, Gorilla, or G4.