Hatch fills or pixel art plotting requires a rather precise estimate of your particular pen/paper combo’s stroke width.
For example, this test pixel art plot would benefit from a slightly thinner pitch to avoid the visible overlap between neighbouring lines:
There is no way around experience to find the optimal pitch. I’ve created the
fill_test sketch to create custom charts with test patterns precisely tuned to the pen of interest. There is indeed no point to testing a rotring isograph .35mm pen with a generic 0.1mm to 1.0mm chart.
Here is how the UI looks:
Beyond the general layout options (page size, grid size, etc.), the
Smallest Width and
Width Increment parameters enable a fine-grained exploration of pitches around the nominal pen size.
Here is an example with a rotring isograph .35mm in my notebook, which has a slight propensity for ink soaking. For this combo, fills with .4mm pitch yield the best results:
$ vsk run path/to/sketchs/fill_test