Methods, systems, and apparatus, including computer program products, for generating a design image for manufacturing a designed object. In one aspect, a method includes receiving input specifying a visual design of an object in a first image, generating a second image based on the received input, mapping the second image to a surface having one or more contours based on one or more flow lines to generate a third image, presenting a composite of the third image with the first image, and providing the second image to an automated process for manufacturing the designed object.