Question

How do I print double sided if the option is grayed out on my Mac?

Community Answer

That probably means that your printer can only print one side at a time, so you will have to print double sided manually. You will have to print just the odd-numbered pages first, then you will have to rotate the pages you just printed and put them in the paper tray facing downward and print the even-numbered pages on the backside of the previously printed pages. Experiment a bit so that you can be sure which way to orient the pages.