Water marbling due to differences in density

In my last video the girls and I investigated density by layering olive oil and water. We found that oil floats on water and this is due to water molecules having greater density. Specifically, water has a density of 1 g/mL and cooking oil is about 0.92 g/mL. If you are interested in learning about how we can determine the density of a liquid just let me know! Anyhow, to continue on with this theme I tried my hands at water marbling with nail polish and water. I soon discovered that this was not an activity for the girls. The paint fumes were too much. So, I did this one on my own. After a few tries it was pretty easy. One thing I learned is that it will not work in the cold. I tried doing it outside with little success. The paint would not spread on the water in cooler temps. We can figure out why this is as well if anyone is interested. Here is the activity sheet and link so you can print it! I will add the video next.