You can use the print functionality of your browser to print our proofreading results to paper or to a PDF file. When printing, you need to select the print option for "Background graphics" in order for the highlighting to appear.

In the Chrome print dialog, you can find this option under "More settings" and it looks like this:

Printing of proofreading results is not currently available from the Word add-in, but we are working on adding this.