Nail polish inside a mason jar

using nail polish on the inside of the mason jar could be risky; but I did see a really neat technique on the outside. The nail polish is floated on water and the jar is dipped into the nailpolish. Check out this link.

https://milaslittlethings.com/2014/03/diy-mason-jars-art.html

The nail polish might be flammable.. use a battery tea lite or put the nail polish on the outside.

Be safe paint the outside.

I know you're trying to get that high gloss look from the paint being on the inside. After you've painted the outside use a spray sealer that is super thick. It's sold at hobby stores. It will give you a high gloss look. Just spray several thin layers letting it dry between layers.