Hand-painting: a technical technique applied to hand-painted patterns in various industries, such as design hand-painting, which is mainly the research hand-painting in the early stage of design scheme and the performance hand-painting of design results. The early stage is called sketch, and the result part is called performance drawing or effect drawing. Hand-painted content is very broad, and the text cannot be fully expressed;
Sketch: refers to the drawing method of depicting the outline, volume, structure, space, light, texture and other basic modeling elements of an object with monochrome or simple color tools. It is the foundation of all painting, which can cultivate basic observation ability and painting ability.