Comment by kuerbel
13 hours ago
In Germany there is a thermal paper that is considered food contact safe
https://www.koehlerpaper.com/en/products/Thermal-paper/TH_Bl...
Maybe someone sells this where you live? I have found a shop in the US: https://www.ncco.com/blue4est/
Searching for blue4est was the key.
I just checked and there is even a seller on Amazon delivering in the U.S., so it shouldn't be too hard to get.