Making holograms with a pen plotter

A maker with a slightly cursed-but-beloved pen plotter has pulled off the kind of project the internet lives for: turning oily fingerprint smudges and shiny lines into homemade holograms. The article walks readers from olive oil on a phone screen to reflective patterns that seem to float in 3D, and the community absolutely ate it up. The loudest reaction was pure nostalgia. One commenter called it “old Internet” fun, the kind of weird, clever experiment people miss: messy, surprising, and just educational enough to make you feel smarter for clicking.

The biggest crowd-pleaser was the greasy-finger demo, which commenters loved because it takes something everyone finds gross and annoying—screen smears—and turns it into a lightbulb moment. That “wait, my dirty phone is science now?” energy carried the thread. Then came the classic comment-section escalation: not just praise, but instant attempts to upgrade the contraption. One person dropped a throwback link to abrasion holography from 1995 and casually suggested swapping the pen for a needle, while another went full mad scientist and proposed adding a tiny piezoelectric scanner for finer detail. In plain English: the comments went from “neat!” to “how do we make this even weirder?” in record time.

There wasn’t much fighting, but there was a familiar maker-world flex: half the room marveling at the elegance, the other half already planning the sequel. Toss in a Steve Mould explainer, and the vibe became science fair, nostalgia trip, and garage-lab chaos all at once.