What’s the difference between water based enamel, and oil based enamel?
Water based enamels have far less odour, have shorter recoat times, never yellow and, well, you can wash them off with water. So why would you use oil based enamels? Because they have better abrasion resistance, they dry hard with a smooth finish, retain a higher level of gloss, and give you more time to work the paint. Sadly, they do tend to yellow over time.