Deposit slips, Checks, and some other forms you print in QuickBooks are actually PDF documents.
Generally, most browsers can display and print PDFs without using Adobe Reader, although the results are sometimes unpredictable. (Chrome is the most reliable for printing in QuickBooks).
To better control printing, you can set a preference in your browser so that PDFs are always viewed and printed using Adobe Reader. You can download Reader for free.
Each browser has a different way of setting this preference. Visit the Adobe site for specifics.
If you decide to print using Reader, set these options in the Paper Size & Handling section of the Print window:
If you decide to print with your browser, be sure to print using actual size. This means you may need to clear any options or properties that scale, shrink, or fit to size.
Print checks: What do the horizontal and vertical numbers mean?