I’ve noticed that when I export plots in Mathematica without a background, a lot of the text ends being made of semi-transparent pixels. For example:

myplot = ContourPlot[Cos[x] + Cos[y], {x, 0, 4 Pi}, {y, 0, 4 Pi},  PlotLegends -> Automatic] Export["Output.png", myplot, Background -> None, ImageResolution -> 150] 

Notice how several of the numbers on the axes contain semi-transparent pixels. In general, is there a way to avoid these altogether while still maintaining the transparent background? The final product still has to be a raster image, unfortunately, so SVG or EPS won’t be able to save me here.

I also have this problem when I try to use MaTeX, not just in the simple example above. A lot mathematics it renders gets exported with semi-transparent pixels as well.