You can specify a percentage of a document’s original size to reduce or enlarge any printed document in Safari.
With a tax forms document open on your Mac:
Choose File > Page Setup.
Click the Settings pop-up menu and choose “Page Attributes”.
Click the “Format For” pop-up menu and choose “Any Printer”. This sets the document’s scale for all the documents you print from this app.
Choose File > Print. If you see a “Show Details” button, click it to show all available options. Set scale to 100%
Tweaking your print alignment
If you find your alignment is slightly off, you can make small adjustments in alignment through Tax Forms Helper’s print menu.
If you glance just above the “Print onto Pre-Printed IRS Form”, you’ll see the powerhouse feature that lets you modify your data alignment.
Adjust alignment
You can move your data right, left, up or down using the adjustment indicators on the Print Menu.
Return to the Tax Forms Helper print menu to make alignment tweaks.
Simply enter a number in the hundredths box and select right/left or up/down from the dropdown options to adjust.
You can return to adjust the alignment as needed after each test run until you’re satisfied with your results.
One more alternative: printing from Adobe Acrobat Reader
If you’re still having trouble with alignment, you can also try printing from a pdf in Acrobat Reader. Some users have great success with this technique after all else has failed.