A salt map is created when showing land forms on continents. To make the dough, you will need salt, water, and corn starch. Mix 2 cups salt with 2/3 cup water, heat to dissolve the salt and remove from heat. Mix together 1 cup corn starch and 1/2 cup water, then mix into the saltwater mixture. This should create a stiff dough. Let dough cool and wrap in plastic or foil to store. This recipe yields enough for 2 sheets of 9×12 paper.