Hi Joel,

I use a barcode font from Carolina Barcode. Normally print about 3/4" 3 of 9.
The package came with many different sizes but honestly not sure the largest they support.

Just select the barcode font and print the numbers/characters with an "*" at each end.
If you use the lower case font, the numbers are printed below the barcode.

Check out http://www.carolinabarcode.com/

HTH

Al