There is a problem to use acrylic paint for underpainting for an oil painting. It is not advisable to use acrylic paint for an underpainting. There is a reason for that because it has not had enough “tooth” to give the oil paint a foothold on the acrylic surface. To use acrylic primer is ok to use.
The reason for acrylic paint not to be a good underpainting is, white included, it dries to a hard, glossy surface, which can be a poor surface upon which to apply oil paint.
There are different colors in the acrylic primers, but it is very limited. The best use case for this is for monochrome underpaintings. This you can do with a white and black primer, mixing the two acrylics together and making greys.
Helen van Wyk an American artist do this all the time. From Helen van Wyk’s book “Welcome to My Studio”, and I quote pages 44 and 45: “I assume that the Old Masters did their underpaintings with egg tempera. Acrylic paint, I believe, is the 20th century’s version of tempera, the oldest painting medium known. You have no doubt heard that you can’t mix oil and acrylic together, or paint acrylic over oil. I heartily agree with these two warnings. I disagree with the admonition that you can’t paint oil over acrylic. I’ve been applying oil paint over acrylic underpaintings for more than twenty-five years with no disastrous results…… Whether I’m doing an underpainting for direct application or one for glazes, I make sure that the acrylic is applied thinly enough to maintain the texture of the canvas. Any thick buildup of acrylic would impair the adherence of my oil paint to the underpainting.” (She also lets the acrylic underpainting dry thoroughly before proceeding.)
Some people’s opinion is that to use a good professional grade acrylic you will not have a problem with the “plastic, glossy” issue. On my research on the Internet, I read that there is a person which really water the acrylic down, and doesn’t find any problem with that.
My personal opinion is that I try to avoid this kind of practice and would like to see that my paintings have a very long life span. Therefore I doubt that I will use acrylic as an underpainting medium.
By Pieter Lategan