Halitech's way is how I do it. Only difference is I usually only let it set in the bag for 15-20 minutes, remove it and let it dry overnight. Oh, I also have a thin piece of plywood that I place in the bag under the tool and leather. It helps to form a nice, flat flange for stitching. I've been carrying this one for about a year and it has held it's shape really nicely. (not that I'm any kind of expert )