# How to make plots 'blacker'?

I need to make a contour plot for publication, but even if I set ContourStyle->Black, the 'black' plots and the axes are very faint. When I export the figure in svg and open it in some image-processing software (inkscape), the colour shown for the selected plot is actually a 'gray' colour instead of 'black' in rgb scale.

As shown in the figure, it is obvious the dashed line is a lot darker than the gridlines and tick markers. How to make the Gridlines, the tick markers and everything appear darker (not thicker, I am happy with the current thickness)?

• What if you save the graphics as a pdf? – anderstood Nov 5 '16 at 18:32
• Does ContourStyle -> Directive[Black, Opacity[1]] help? – user484 Nov 5 '16 at 18:40
• Setting the Opacity and GrayLevel does help. Thanks. But that only applies to the contour lines and still I don't know how I can make the tick markers (2, pi, pi/2, etc) darker – Physicist Nov 5 '16 at 18:44
• ..., FrameStyle -> Black] should drive frame components, including tick marks, to Black. – Marchi Nov 5 '16 at 20:03
• yeah FrameStyle->Black does make it work. thanks! – Physicist Nov 6 '16 at 13:08

I'm not actually sure how to test your specific case, but this seems to work:

cp = ContourPlot[x^2 + y^2 == 2, {x, -2, 2}, {y, -2, 2},
GridLines -> Automatic, GridLinesStyle -> Black,
PlotTheme -> "Monochrome"]


List@InputForm@Cases[cp, _?ColorQ, Infinity]
(*
{{GrayLevel[0], GrayLevel[0], GrayLevel[0],
GrayLevel[0], GrayLevel[0], GrayLevel[0]}]}
*)

Cases[cp, _Opacity, Infinity]
(*  {}  *)