From Pub 2003 help file (Searched for mirror text):
Print a mirror image (as for a t-shirt)
Before you begin, you will need to get thermal t-shirt transfer paper for
the type of printer that you are using. The paper is available at office
supply stores.
1. Create your design in Publisher.
2. On the File menu, click Page Setup.
3. Click the Layout tab.
4. Under Publication type, click Full page.
5. Click the Printer and Paper tab.
6. Under Paper, in the Size box, select Letter.
7. Click OK.
8. Do one of the following:
-If your design is a picture, clip art, or WordArt, flip it
horizontally.
How?
1. On the Arrange menu, point to Rotate or Flip.
2. Click Flip Horizontal.
-If your design includes text in a text box or table, turn it into a
picture first, and then flip it horizontally.
How?
1. Select the text in the text box or table in your design.
2. On the Edit menu, click Cut.
3. On the Objects, click Insert WordArt .
3. Under Select a WordArt style, click a style, and then click
OK.
5. Press CTRL+V to paste your text into the WordArt Text box.
6. Format the text, and then click OK.
7. If necessary, resize the WordArt, or use the WordArt toolbar
to format it, and place it in the design.
8. Select all the objects in the design, including the WordArt.
9. Click Group Objects .
10.On the Arrange menu, point to Rotate or Flip, and then click
Flip Horizontal.
9. Print your design on plain paper first to make sure it looks the way you
want it to.
10. Make any adjustments to your design after seeing the test printout.
11. Make sure thermal t-shirt transfer paper is in the printer.
12. On the File menu, click Print.
13. Select the options you want.
14. Click OK.
