I bought a block of white styrofoam that was 2' T X 2.5' W X 8' L from Home Depot to make a R/C boat. Go to the special services desk and you can special order it. It was around $50.00. I also use the 2" thick sheets of styrofoam house insulation that you can buy at Home Depot right there in the store (no special order). I make my Giant Delta's out of this.