The Robot character was originally designed for a sci-fi movie project that I wanted to make with my kids. I was originally going for a car factory robot look. The outside is covered in a yellow or black PlastiDip type texture with metal underneath.
The clean robots were textured with Blender’s default material system. The rusty one was hand painted between Affinity Photo and Blender’s painting environment. The dark robot was textured and rendered in Octane for Blender.