Conceptual design using conventional 3D CAD systems is a controversial issue among industrial designers. Although one can produce complex, accurate, finished 3D models using these CAD systems, it is still difficult to use them during early, creative product design. In this paper, a method is described that allows the design of protrusions and depressions in sculptured surfaces in a flexible and interactive manner. Through interviews with industrial designers, the basic requirements for support of such functionality during conceptual design have been formulated. An implemented method based upon these requirements has been extensively evaluated by industrial designers, and these evaluations show that industrial designers find this functionality extremely useful during conceptual shape design.