This paper introduces DressUp, a computerized system for designing dresses with 3D input using the form of the human body as a guide. It consists of a body-sized physical mannequin, a screen, and tangible prop tools for drawing in 3D on and around the mannequin. As the user draws, he/she modifies or creates pieces of digital cloth, which are displayed on a model of the mannequin on the screen. We explore the capacity of our 3D input tools to create a variety of dresses. We also describe observations gained from users designing actual physical garments with the system. Author Keywords Clothing design, DIY, craft, tangible interaction, 3D drawing ACM Classification Keywords H.5.2 Information Interfaces and Presentation: User Interfaces—Interaction styles. General Terms Design, Human Factors