This stuff looks interesting. A polystyrene foam from Germany. Do a search in Google on “De-Q-cell” and click on the “translate this page” links. Apparently it’s an “Expanded polystyrene hard foam with particularly fine-crystalline cell structure” That “Guarantees high pressure strength, inherent stability and tenacity (rerising ability after removal of the load)” at 17kg/m3 it’s superlight and a bit cheaper than Polyurethane. Anyone know anything about it - European guys?