Font issues when increasing vertical spacing on iTerm2

[sheerun]

http://d.pr/i/rRtx

[Lokaltog]

This is most likely an iTerm2 problem and impossible to resolve in Powerline. iTerm2 appears to pad the lines with the background color included (which makes sense), so the only way of resolving this would be to remove all background color from Powerline and only use foreground colors, unfortunately.