Create a method of making blocks in CAD. Select a graph, enter the b command, and the block definition dialog box pops up. Name the block as shown.
Click OK, and the block is completed.
Knowledge expansion: how to print CAD drawings in black and white
Print a style sheet, select one from the drop-down list, or create a new edit. (Click Edit on the right side of the style sheet to enter the setting interface)
Enter the format view and feature color bar, drop down and select black, save and close, so it will be black. As shown in the figure: