Early pioneers of computer graphics used plotters (e.g., Frieder Naake, cf. [10]) and also robots (e.g., Ken Goldberg [11]) to create art works, numerous others could be listed here. Today, a number of artists use such machines, but typically their main purpose is to create abstract and artistic paintings. Ben Grosser [12] and Holger Baer [13] are typical representatives. Zanelle [14] by van Arman is a specialized plotter to create pop-art like paintings and also somewhat more realistic portraits. An interesting painting machine is Vangobot [15], also a specialized plotter, that uses a paint mixing hardware to create color variations. To our knowledge, none of the mentioned approaches uses a feedback loop for optimization.