To choose between these two similar painting mediums, acrylic and oil, one must learn what the primary differences between them are:
Speed of drying
Acrylic dries extremely quickly. A few layers of the paint will dry in just minutes, while the thickest portions will dry in about an hour. Oil, on the other hand, can take days before it completely dries.
Because of this, beginners are advised to use oil because it allows for corrections of mistakes and provides longer working time. If the painter decides to take a break and resume his work the next day, he is able to do as the paint on the palette would still be wet and usable, while the colors on the canvas can still be blended with new paint.
Those who use acrylic typically apply a lighter shade of the colors they use because the paint turns darker when it dries. The opposite is true for oil as it produces no immediate color shift.
However, in the long run, acrylic might prove better in terms of color quality because how the colors looked when they dried will still be the same even after two centuries. The same cannot be said about oil, which will acquire a slightly yellow tinge after a few decades.
Acrylic can be painted directly on any canvas or surface, making it a flexible medium. But oil paints can cause corrosion on the work surface, therefore it is necessary to prime the surface first, be it canvas, board, or even paper.
Jonathan Schrag here, a BYU art student. I am currently majoring in acrylic painting, clay sculpting, and wood art. I dream of one day building my own gallery. You can track my progress by following me on Twitter .