ggplot2 make legend key fill transparent

Question

I am trying to make the legend key fill for a ggplot transparent. I followed the instructions on one of Hadley\'s ggplot2 guides for changing the legend key fill, but for some

Answer 1

Additionally to legend.key = element_blank() you can put legend.background=element_blank() within theme(), to make the text transparent as well

This will also make the default white background transparent when using gg_themes