How to turn on invisible characters in Sublime Text 2

By default invisible characters (or whitespace characters) are displayed in Sublime Text 2 whenever you make a selection over some text, but occasionally it helps to see all invisible characters.

In order to do this in Sublime; open your preferences file (On OSx that is ⌘+,) and insert the line "draw_white_space": "all".

By default it is set to "selection" and the other option is for it to be "off".

Why would you want to show invisible characters?

The reason I needed to turn on this feature was because I had copied and pasted a line of code from a website into a Ruby file and it had brought across with it some invisible characters, I was scratching my head for an hour trying to figure it before I posted a question to StackOverflow (https://stackoverflow.com/q/14863720/197302) and some kind soul pointed me in the right direction.