We present a method to generate virtual woodblocks for virtual printing from a gray value image or a full-color image. In this method, the virtual sculpting system extracting features or colors of the given image carve a virtual board automatically. A printing image is synthesized using the woodblocks in the virtual printing system. Using a gray value image as a draft, the sculpting system generates one virtual woodblock that expresses gray values with carving marks, and we can transform the draft image into another one like a woodblock print by using it in the printing system. Using a full-color image, several virtual woodblocks for each color of ink are generated, and we can synthesize a multicolored woodblock print by printing a virtual paper sheet with virtual woodblocks for each color one after another. The methods we propose here are useful in synthesizing non-photorealistic images with computer graphics.