Oil Picture

When we see oil on water, it is usually associated with an environmental disaster. The colored patterns that we see on the water are still very nice to look at. They arise because water and oil do not mix and the oil forms as thin a layer as possible on the water, on which the light then forms interference patterns with beautiful bright colors. We can replicate this in the laboratory without harming the environment and at the same time preserving it over the long term.

The nail polish used in this experiment may stain clothing and furniture.

Materials you need for this experiment:

transparent nail polish	We only need a drop of nail polish.
black paper	We will immortalize the interference pattern (color pattern) on the black paper.
large glass bowl	The glass bowl must be large enough to place the black paper in it.

How to make the experiment:

	If the black paper is too large for the bowl, trim it to fit the bowl. It should be small enough that you can easily pull it out of the bowl. But the bigger it is, the bigger your picture will be, because the black paper will be the canvas for the picture, so to speak.
	Now place the black sheet of paper in the bowl and pour some water over it so that the entire sheet is well covered with water. But don't fill the bowl full with water. The more water you have in the bowl, the harder it will be to get the paper with the picture out of the bowl (without destroying the picture).
	Now drop a drop of clear nail polish onto the water in the middle of the bowl. It will spread across the surface of the water and form colored interference patterns. Now wait a few minutes until the nail polish is dry.
	When the nail polish has dried, carefully pull the black paper out of the bowl. It is important that, if possible, the entire image that the nail polish has formed on the water surface lies on the black paper.
	Then let the black paper with the nail polish dry somewhere. Be careful, however, because some types of black paper stain themselves when they are wet and this can cause stains on the surface. When the paper has dried, your picture is finished.

Experiment with different nail polishes (thick, thin, different solvents,...). Which ones give the most beautiful pictures?

Have fun experimenting!