Valid for Moodle 2.8. Updated on 7/21/2015.The simplest way to print a forum is to use the print command in your browser. You may want to dock your blocks to simplify the print out.
Unfortunately you can only print one discussion at a time this way so if your forum has multiple discussions you need to do multiple prints. If you know that you’re going to want to print out your forum, consider using the Simple single discussion forum format. This forces all postings to be part of a single forum. While this may seem restrictive, if you write your forum description broadly enough, the first level messages are the equivalent to the discussion threads in other formats.