Ink/pen dynamics and the rhythms of writing

[oshfdk]

I've found the same kind of sharp transition from the dark to light ink in EVA y on You are not allowed to view links. Register or Login to view. (marked with a red arrow), so it's not limited to EVA q's. Could this be a retouch job?

By the way, there is a barely noticeable second stroke to the right of EVA y above (marked with a grey arrow). This looks like an image artifact, but it's also present in MSIs, so could be an actual very faint stroke.