Found a notebook in a library book with a recipe for 'invisible ink'
I mean, it was just a regular composition book tucked in a cookbook at the local branch. The page said to mix lemon juice with a little water and write with a toothpick, then heat the paper to reveal it. I tried it on some printer paper and held it over my stove. Instead of neat writing, the whole sheet just turned a gross brown and curled up. Maybe my heat was too high? Has anyone else actually gotten one of these old tricks to work without ruining the paper?
Yeah, that "super low heat" thing is way off... A light bulb won't cut it for most stuff. You need a steady, even warmth, not just a tiny hot spot. Trust me, @charles_lewis14, that advice will leave you cold in a bad way. Seen it happen too many times. Gotta have a proper heat source.
Right? What are people even thinking with the light bulb idea. I tried that once for seedlings and they got all leggy and weak because the heat was so uneven. You really do need something that spreads the warmth out.