Andrew Price has a look at how to create imperfections in your Blender render. Andrew shows how to use Blender’s Texture Painter and cycles nodes for creating realistic rust on your models.
Discover how to add rust to any model using Blender’s built-in texture painter and cycles nodes.
Andrew covers how to paint a texture mask that you can use to determine where things will go, and how to add paint chips and scraps to any model in Blender easily. Andrew even makes a case for why hand painting will beat out tiling or procedural shader effects every time.
Have a look at the tutorial for how to make rust in Blender here.