Fact is that nothing looks like real metal except real metal. And micro foil adhesive is a very easy and very inexpensive way to apply real metal in the form of metal foil to your models. The most common foil is ordinary household foil which most people have at home. But with a little checking around you will find that there is also stainless steel foil, copper foil, etc. The softer and thinner foils are the easiest to use, but the surface you want to metal clad is not too tough, you can use anything.