Because I am actually allergic to oil paint and harsh solvents, I can only use acrylic paint, but in all honesty, it's not the end of the world. I do prefer the creamy, rich consistency of oils, but acrylic dries faster and more importantly, doesn't adversely affect my health! Various additives can both prolong drying time in acrylics as well as change their consistency, so you can have the best of both worlds.