why does my 2 pixel size outline looks blurry

[HSDSZ]

Here is the outline width = 1 pixel, which looks normal

If I change the width to 2, I suppose i could get a sharp 2 pixel outline, but the result is kind of blurry

here is the render setting.

[pragma37]

Technically, the line is centered at one pixel, so a 2 pixel wide line will cover 100% of that pixel and 50% of the contiguous ones (so 1.0 + 0.5 + 0.5 = 2.0).

I know it can seem strange, but I've made tests in the past where I've tried to "push" even-width lines to one side so they're aligned to the pixel grid and the transitions between different line widths look really bad.