Engraving a PETG sheet with a diamond drag engraver on the Sherline and filling the scratch produces a good-looking hairline, but there’s a tradeoff between having the protective sheet pull the paint out of the scratch and having the crayon scuff the unprotected surface. This time around, I scribbled the crayon through the protective film, let it cure for a few days, then scraped the surface to level the paint and see what happens.
First, an unscraped cursor:
Peeling the transparent protective film:
The hairline is solidly filled:
Scribbling another cursor the same way, then scraping the protective film to flatten the shredded edges:
The hairline remains filled, but not as completely:
A closer look:
Scraping the crayon off the film removes a substantial amount of paint from the hairline, but, on the upside, the protective film does exactly what it says on the box and the PETG surface remains pristine.
Both hairlines are, at least eyeballometrically, Just Fine™ for their intended purpose.