Saving to PNG adds lines back when linewidth=0

[joshday]

I opened an issue in GR, but this is possibly due to how Plots treats line widths.

https://github.com/jheinen/GR.jl/issues/147#issuecomment-419614495

[daschw]

See also https://github.com/JuliaPlots/Plots.jl/issues/1416. You can use linecolor = invisible() as a workaround.

[daschw]

Or probably linealpha = 0 is also sufficient.

[daschw]

But i think we could include this workaround in the gr backend code.

[giancarloantonucci]

Neither linecolor = invisible() nor linealpha = 0 work for me when saving to PDF. What am I supposed to do instead?