How to change the mailing label font
When you are on the print preview screen, in the upper right corner, choose RTF where it says PDF, then click the blue disk icon (Save).
Open the saved report in MS Word.
Use Ctrl + A to select all text and change the text up to size 10, or maybe 11 font, but not 12 (because that's too big to print with the proper formatting).
Print the labels from MS Word.