I'm working on a crafts project that is basically putting oil, water and glue in a bottle together with glitter just so you look at it. I want to see how it looks if the density of the oil is very close to that of the water-glue mixture.
The oil I'm using is baby oil, which sits on top of the water, so I need to increase its density. If I had wanted to increase the density of the water, I would just have added salt. Now I was thinking if there might another dense solute that I could dissolve in the oil to make the density do up, but I found that search engines interpreted my search terms in the wrong way and I couldn't find any.
That's why I'm here: to find a suitable solute. Originally I was thinking of powders, like the example of salt in water, but a dense liquid would also work. It would need to be something that's readily available commercially, and preferably not too expensive or dangerous.
Are there any dense solutes for oil that match my criteria?