Abstract: We propose a sketch-based system to design volume data from scratch. The user splits a surface model and paints brush strokes to volumetrically fill the 3D space. We extend exisiting sketch-based modeling systems in various ways. First, we use the cross-sectional plane as the interface to design internal structures. Second, the predefined surface geometries are used to guide the synthesis process from 2D cross-sectional information to 3D spatial distribution. Third, the 3D solid modeling process is decomposed into two phases: space division and color particles distribution. The user divides the space into multiple regions, each of which corresponds to an uniform texture. The texture is designed by distributing particles in the regions, guided by the surface geometries that define the boundaries. We performed a survey to examine how people associate 2D cross-sectional information to 3D, and reflected the result in designing the system. Our system is capable of producing a wide variety of non-photorealistic volumetric objects such as foods, anatomic/biological models or furry models.