>>6772831It's all pink insulation foam. You can get it at home Depot, and cut it with a hot wire cutter (there's some cheap ones on Amazon). I took a ruler and used a ballpoint pen to make the lines by pressing hard enough to make an indent. Then I painted it all dark grey, then layered dryer and dryer-brushed layers of lighter grey.
I used the same tool and material here, but with some shrubbery from Michael's
