mapbox/tilemill — pull request #2109 by geografa (2013-10-21 22:58:52+00:00)
Title: Adds info on blank tiles issue where tilelayer has background but none i...

...s set for global. There doesn't seem to be a great place for this so I'm pointing it out in the TileMill Guide. Let me know if you think this belongs in a different FAQ.
@springmeyer