What carving technique is this?

Shadow Carving-Pure stone materials such as Moyu and Shanxi Black are used. After being polished by water mill, the outline of the image to be carved is drawn on the polished surface. According to the principle of black and white light and dark imaging, a special needle-shaped fine alloy steel head tool is used to express the image by adjusting the density, depth and dotted line of the needle point through wrist force. No mistakes are allowed in the carving process, the first thing is "wrist strength", and the requirements for "eyesight" are more stringent. Shadow play sculpture not only has the same artistic effect as photography and optics, but also embodies the painting technique and has unique artistic charm. Widely used in mural decoration, portrait and desk decoration, it is not only a gift handicraft, but also a work of art with high artistic appreciation value.