We present Object-Oriented Drawing, which replaces most WIMP UI with Attribute Objects. Attribute Objects embody the attributes of digital content as UI objects that can be manipulated through direct touch gestures. In this paper, the fundamental UI concepts are presented, including Attribute Objects, which may be moved, cloned, linked, and freely associated with drawing objects. Other functionalities, such as attribute-level blending and undo, are also demonstrated. We developed a drawing application based on the presented concepts with simultaneous touch and pen input. An expert assessment of our application shows that direct physical manipulation of Attribute Objects enables a user to quickly perform interactions which were previously tedious, or even impossible, with a coherent and consistent interaction experience throughout the entire interface.