You can view all tasks with "view all" in the search area. Though this will not include completed tasks. If you'd like to print completed tasks, you can view all completed through the Karma score at the top, then Print Current Page (top right gear icon)..
Using the suggested "va" filter to list all open projects. When printing however it goes on for 3 pages as the font is very large.My workaround for a single page list is to -zoom out (Chrome browser) so all projects show-use Windows 7 Snipping Tool to grab the list
Another alternative -- which works better for me, is to click on the "Task Actions" icon (faint grey editing icon) on the upper right corner of the project list.
Then "Export as Template". This will save your list in a plaintext .txt file -- perfect for printing out in a normal size font, or, for that matter, using for any other purpose: You'll have a plain list of your items in that project.
You can also do that from "Inbox" which I find handy.
Unfortunately, you cannot yet "Export from Template" in the filter views, which I do hope will eventually be implemented, as its very useful in any view to be able to export a plaintext list.