Colin Litster has a great example of how to create a copper plated roof in his book Blender 2.5 Materials and Textures Cookbook. The the image files of the are available from the publishers website, naturally they are copyright protected, which reduces their usefulness greatly. Furthermore the book gives good details on how to apply the images as textures in Blender, but the information on how to obtain/create the base image is sparse to non existent. Searching the web did not result in any image that would be usable. Therefore I set out to create the images from scratch.