I learned today that wikia includes a built in stylesheet for producing a printable format for every article. If you have ever printed a webpage, you know that most of the time it comes out really bad. There are huge navigation bars, things are spread over multiple pages, etc. Not so with wikia! Just by printing the page you will automatically make use of the printable format! You can check out what any page will look like by adding &printable=yes to any full page url.
For pages with spoilers, make sure you open the spoiler block before printing!