Jake & Memphis were going through our Kids Concoction book and found a “recipe” for invisible ink.
You need lemon juice, paper, a bowl & a cotton swab.
The kids put their cotton bowl in the juice and started to write messages.
The only thing is that the paper got really wet. You could see exactly what they were writing.
We waited awhile to make sure they were dry, but the paper wrinkled up where the writing was so you could already see what it said. I did however still try to hold it up to a light bulb – nothing. Then I held it over a toaster as recommended to see the lemon juice turn a darker color. It never happened. My hands got hot and there was no reaction so we gave up. Maybe the lemon juice was old? Maybe we needed different paper, although we did use a thick computer paper, no matter what it was, the kids were sad that this didn’t work out.