Regnbue-papir (rainbow paper, petrol paper)
https://www.youtube.com/live/20vkOIyUmCA?feature=shared
https://www.kiwico.com/diy/art-creativity/quick-easy-crafts/rainbow-paper-experiment?srsltid=AfmBOoqSkNFoZ18qR2YE7w4U74UWtp1hd86rthefhOXhau5EaViUvRbL
https://sciencekiddo.com/rainbow-paper-kid-color-science/
https://www.instructables.com/Rainbow-Nail-Polish-Paper-Experiment-and-Craft/
https://www.nisenet.org/sites/default/files/catalog/uploads/9881/diy_nano_print_rainbow_film_03_21.pdf
https://www.wired.com/2012/06/water-marbling/