Vinyl panels
First vinyl panel installed in "Motoko"'s forpik!
That prooves the concept of making them from sleeping matt (liggunderlag) and vinyl cover. Lightweight, can be easily removed (mounting on velcro) and provides heat isolation!
Last but not least: can be done at home, in warmth!
Meanwhile I started renovation of koj bottom plates (marine plywood)
I'll paint them white, of course!