Acrylic is basically a plastic, and as such does not age. Oil paint, on the other hand, gains a mellowness as it ages, a patina, and gentle cracking, and a flowing together of the layers. It is particularly effective in such painterly effects as chiaroscuro, and in the technique called “plein aire”. For the painter, the oil paint stays smooth and fluid on the palette longer than acrylics, and mixes with several media, while acrylic does not provide so much variety. Oil paint colors are subtler and richer, and the gentle glow of the painting grows as the painting ages. The only advantage of acrylics is the price. Finally, there is the “visual art history” the artist becomes part of with oils.
Acrylic is a thicker paint, Oil works better in the long run as you can paint over it several times without a difference in thickness. The effect is also completely different. You can compare it like crayons to watercolour pencils (the pencils being oil and crayons being acrylic). These paints are completely different and the only real advantage depends on the item you are painting.
I've been painting for a couple of years now and my favorite paint medium has always been acrylic.
However, there are advantages to using oil paint rather than acrylic paint:
- Blending is never a hassle because colors blend well with each other since the paint takes a longer time to dry.
- If you suddenly feel like not painting, setting aside the painting will not make it dry quickly; therefore, an artist has an easier time blending and painting on the canvas.
- The colors themselves are brighter and there is a variety of colors to choose from.