How to Use the MIrror Command in AutoCAD

By Bill Fane

The MIrror command creates a reverse copy of an object in AutoCAD. After you select some objects, AutoCAD prompts you to select two points that define a line about which the objects will be mirrored. You can then retain or delete the source objects. Follow these steps to use the MIrror command:

  1. Press Esc to make sure that no command is active and no objects are selected.
  2. Click the Mirror button on the Home tab’s Modify panel, or enter MI and press Enter.
  3. Select at least one object, and press Enter to end the object selection. AutoCAD prompts you to define the mirror line by picking points: Specify first point of mirror line:
  4. Specify the start of the mirror line by clicking a point or typing coordinates. AutoCAD prompts you: Specify second point of mirror line:
  5. Pick a second point. Most of the time, you’ll enable Polar Tracking mode or Ortho mode so that you can mirror objects precisely. You can also use object snaps on existing objects, including ones being mirrored, which ensure exact symmetry between the source and the mirrored objects. AutoCAD now prompts you: Erase source objects? [Yes/No] <N>:
  6. Finish the mirror by using one of these options:
  • Type Y at the final prompt. The source objects disappear, leaving only the new, mirrored copy.
  • Accept the default No option. The source objects are retained along with the mirrored copies.

Normally, when you mirror text or dimensions, the words read backward. The system variable MIRRTEXT can handle this little problem. By default, MIRRTEXT is turned off (that is, its value is 0), so the text itself still reads the right way around after the objects are mirrored. If you really want your drawing text to appear in reverse, change the value of MIRRTEXT to 1.