Changing staff line width (thickness/weight)

I have a simple question that I haven't been able to figure out...

Musescore seems to have opted for same width of the staff and bar lines.

I would ideally like to change the staff line width while keeping the bar lines similar to the defaults, but if that cannot be done, then changing both to a smaller width is also OK for me at this point.

The problem I have is that, on my printer, the lines appear visually too strong and makes it a bit harder to read the actual score that what I'd like.

So ... how do I change the line width of the 5 staff lines? I can do this in some other programs and print out nicely looking scores according to my taste, but I have some difficulties doing this with Musescore which I would prefer using.

Thanks in advance for any help or input,

-- Per.