Step 1: Tools and Materials
Free weights (for "clamping")
You'll need a book that is a little larger than the object you are making a case for. The kindle measures 7 1/2" x 4 3/4" x 7/16". The book I used measures 8 1/2" x 5 3/4" x 1". I considered many books, and spent some time looking at some old books trying to find one with a clever title, like Fahrenheit 451, or Catching Fire, but ultimately settled on a sketch book that had no title at all, just a clean black cover. It just felt a little more sophisticated.
For the foam, I was looking for both dense and firm. In the foam world, density is a measure of how big the cells of the foam are, and firmness is a measure of how hard it is to compress. I found a kick board that was being thrown out at a local pool and while it felt a little too rigid at first, after cutting it to size it was perfect. I also considered using wood and strategically placed Sugru, but the foam kick board proved easier for making adjustments.