Just checked out Ofnuts' path tools page. There's a new awesome python plug-in called Engraving Lines.
Loving the results this can generate, all gimpers must test it out!!



Paths were done with periodic wave path tools and inbetweener, following the html readme.
Some extra steps added to the initial outcomes to achieve custom look.
Duplicated original layer on top. Saulgoode Quantize: 12 colors, Smoothing 3, Rounded. LCh Color mode.
Duplicated that again, color mode pin light, opacity 60-100%

Franklin with sine wave path.



Da Vinci, elliptical path with a bit of asymmetry. Inbetweener stretch was set to swing.



Vlad the Impaler after initial run using triangle wave path.



Same with mentioned extra steps.

I'm glad you enjoyed that Nidhogg,
putting electronic scan lines all over people who have been dead for centuries is another reason Finland is the happiest nation on Earth.

I believe individual happiness is something that you can't measure easily, but maybe things like social equality, stability, good education etc. create something you could call general happiness?
Denmark has also been often #1, I used to think LEGO must have something to do with it

Testing more with straight lines.
I want to find good settings for 512x512 images.

90-100 paths.
Line width stepping 0.5
Minimum Luminance 15-30%.
Blur 2.0, keep layers.
Cap styles don't matter as they go over the canvas.

Going further into history.