1. width: create a rectangle of 420,297.

2. Drawings: offset inward by 5 units (according to national standards, the binding line size of A3 drawing is 25mm, and other margins are 5mm).

3. For the binding line, select the new offset rectangle and move the two grips on the left 20 to the right to get the binding line margin.

4. Alignment marks Alignment marks shall be drawn at the midpoint of each side of the drawing and shall enter the frame for 5 mm..

5. The title bar is located in the lower right corner of the drawing, and its size is generally 240*40mm. The size, format and partition of internal tables shall be determined according to the engineering needs.

The title bar can use ATT and w commands to create enhanced property blocks.

6. Sign column The sign column is located in the upper left corner of the drawing, with the size of 100 mm× 20 mm, and the profession, name and date (year, month and day) represented by the countersigner should be filled in the column; When one countersign column is not enough, one can be added, and the two countersign columns should be tied; Drawings that don't need countersignature may not have countersignature columns.