Having a little fun with an antique HP 7440A (HP ColorPro) 8 pen serial plotter.
Used a modern aluminum "universal pen holder" (probably for use with modern single-pen marking machines, or with Roland pen plotters, which have a similar grip mechanism) setup to hold onto a very inexpensive ballpoint pen tube.
It was carefully fine-tuned to barely touch the paper.
I need to modify the plot file though. For some reason, it does not actually change the pen to the holder loaded with my papermate inkjoy black for heavy inking. I will make the change, then re-plot.
The source image is (as far as I know or understand) Royalty-Free, having come from an AI image generator. (IIRC, US Copyright office has deemed AI art to be uncopyrightable). Came from Imagine.art from a text prompt.
I ran it through Drawingbotsv3-premium, which is able to make volumetric shading from raster images (and has a subprogram for spoonfeeding these plotters.)