Waterproofing protects material and increases its longevity. In some instances, such as when waterproofing a tent, it also helps to keep you dry. Any number of materials can be safely waterproofed for any number of purposes. With homemade waterproofing, the material you wish to waterproof determines which method to use. In some cases, the waterproofing darkens or otherwise slightly alters the color of the material. You may wish to test a small area of the material prior to embarking on the entire project if this might be an issue for you.