What are the requirements for the design patent to make 3D lines?

1. Orthographic drawing should be made according to the national standards of technical drawing and mechanical drawing in China.

2. There are no lines such as shadow line, indicator line, dotted line, center line, dimension line and dotted line. Used to express design shapes;

3. Don't draw with pencils, crayons or ballpoint pens, or use blueprints, sketches or mimeographs;

4. The picture resolution should meet the clear requirements;

5. The lines in the drawing shall be uniform and clear, and shall not be altered;

6. The contour line should be solid and thick, and the line width should not be less than 0.4 mm;

7. The picture size shall not be less than 3cm× 8cm and not greater than15cm× 22cm;

8. It should be ensured that when the figure is reduced to two thirds, the details of the product outline can still be clearly distinguished;

9. The proportion of each view should be consistent, and the projection relationship should be corresponding.