The robots are built from various kits and programmed in Java. Although the behavior of each robot is quite different, they share a common architecture and code base. The NXT robots have much more memory so many images can be loaded in a single time. The RCX robots have smaller memory and the image must be loaded in fragments. The robots are designed to handle many different art media -- acrylic paint, pastels, markers, and pencils. The metal robot is capable of pulling heavier loads and can paint with rags, rollers, and wipers as well as brushes. Because the robots are autonomous (stand alone) they can make paintings from 1 ft x 1 ft up to 8ft x 10ft or even larger..