Mike Pan is giving away an awesome procedural metal shader.
This is a painted metal material I created for Blender. The material is a ‘megashader’ that includes effects such as paint peeling, rust, bubbling paint, scratches and other imperfections. The shader is completely parameter driven, and can be used to represent brand-new metallic objects as well as old and derelict surfaces. It’s mostly procedural, and you can even animate the parameters to create changes over time.
The shader is released under CC-Zero. You can use it however you want, even for commercial purposes.