Reliefs primarily include niched, high-relief, low-relief, incised, and hollowed-out styles.
1. Ancient Chinese cave sculptures can be categorized as niche-style sculptures, which, based on different modeling techniques, can further be divided into realistic, decorative, and abstract types.
2. The bas-relief primarily features lines with the surface as a supplement, combining both. Depth ranges from 2 to 5 millimeters. It is thin yet has a sense of three-dimensionality, using sparsity to contrast with density, and the carving technique is refined.
3. Inlaid carving is commonly found on the surfaces of boxes, cabinets, beds, and chests. It eschews drawings, using knives as pens, where the intent precedes the blade, and the patterns are carved with a bright, swift technique.
4. High-relief refers to a form with compressed size and significant undulations, resembling round or semi-round sculptures; such reliefs exhibit a strong contrast in light and shade, with a striking visual effect.
5. The bas-relief is compressed with minimal undulations, maintaining an architectural flatness while also offering a sense of volume and undulation.
6. Line engraving is a fusion of painting and sculpture, created through light and shadow, using light as a pen. It even features subtle undulations, conveying a sense of elegance and reserve.
7. Carving through hollowing removes the base of what is called bas-relief, creating a versatile negative space that has a rhythm of interchanging contours with the positive space. This technique was commonly used on windows, doors, railings, and furniture, with some pieces designed for viewing from both sides.