Texture, Art. This surface would be very bumpy and is a forum of texture art.
Stylized Textures : via PinCG.com
The Art of Justin Messner: Hand-painted Textures via PinCG.com
Chew Magna Fortress, UDK - Page 6 - Polycount Forum
Hand Painted Textures - Seeking Feedback and Crits - Page 2 - Polycount Forum
The Art of Justin Messner: Hand-painted Textures