The lines of patent drawings should be clear, accurate and easy to read. According to different standards and specifications, there may be specific requirements for line type, line thickness and line color. For example, in American patent drawings, lines are generally solid lines with a thickness of 0.35 mm and a color of black. In China patent drawings, lines are generally solid or dotted lines, and the color is black or blue. The thickness of lines is selected according to the size and needs of the drawings.
Therefore, when drawing CAD patents, it is suggested to refer to the corresponding standards and specifications, and choose appropriate lines to draw according to these requirements, instead of just using the default lines. This can ensure the quality and compliance of patent drawings.