The question of whether it's OK to use house paint rather than artist's paint is one that comes up in various contexts, but all seem to be motivated by the desire to save money. People have a variety of opinions, but it is probably best to save money by buying student-quality paints—or saving on paint by creating smaller paintings—rather than using house paint.
Will House Paint Last on Canvas?
Of course, artists can use any kind of media for their art, and the creative use of non-traditional materials is a mainstay of modern experimental creation. Marcel Duchamp's "Fountain" is celebrated for making art out of the most banal and even crudest of objects.
In his blog, Mark Golden of Golden Paints comments on the downside of experimenting with house paint,
"I can’t tell you how many hundreds of times I’ve heard the question 'Can I use house paint?' from artists. If you’re asking for my permission, by all means, go ahead use house paint....The opportunity to create and the materials used to create with are limitless. This is a joyous thing....But then the next question comes….Is it going to last?".... The most significant problem with even a quality house paint is that it will begin to develop cracks [some of which] will lead to paint cleaving off of the canvas."
Golden also points out that the hardening of the paint surface means you won't be able to remove a painting from its stretchers and roll it up or use canvas keys to tighten a sagging canvas.
You Get What You Pay For
Also, remember that with house paint you still get what you pay for, and the cheaper the paint, the less pigment in it. Home repair guide Bob Formisano says, "Most of what you are applying with cheap paint is water or mineral spirits (solvents up to 70%) which evaporate and leave little pigment behind."
Another issue is that house paints don't perform the same as artist paints—they are formulated for quite a different purpose. So don't expect them to mix, blend, or glaze as artist paints do. According to DickBlick / Utrecht Art Supplies, "House paint does not generally perform as well as artists' acrylic in terms of durability, lightfastness, and appearance." Different house paint manufacturers use different vehicles and binders, some of which are more prone to yellowing. House paint may also be more brittle due to fillers and other additives, making it prone to cracking and flaking. Sealing the finished piece with a UV protectant varnish could help with longevity.
As for durability, if you're just painting for yourself, what you use doesn't matter. Or if you're famous (and arrogant) enough, you may believe the preservation of your work is a curator's problem. Or you may be of the opinion that as long as the person buying the painting knows that it is mixed media, it's fine. Ultimately the choice is a personal one, dependent on your intent and style, as well as your finances.
Then again, do you want to be mentioned in history books as a bad example, like J.M.W. Turner is when it comes to the use of pigments that fade?
Famous Artists Who Used House Paints
Scientists have shown that Picasso was one of the first artists to use house paints for his artwork in 1912 to give a glossy surface to his paintings without the evidence of brushstrokes. This was verified by a study in 2013, in which scientists compared the paint used in Picasso's paintings with house paint of the same time period using an instrument called a nanoprobe. The conclusion of the scientists was that the paint Picasso used had the same chemical composition as the house paint, a popular oil-based enamel paint in France called Ripolin. It has been proven to be a very chemically stable paint and thus should hold up well for centuries, according to analysis done at the Art Institute of Chicago.
Jackson Pollock, too, used oil-based gloss enamel house paints for his large-scale poured paintings of the 1940s and 1950s. They were less expensive than artists' paints and came in a form that allowed him to paint in his unique style.
Whereas early-20th-century artists used oil-based enamel paints, bear in mind that most house paint now is latex, which is water-based and not as durable or lightfast as oil-based paint.
Can I Use House Paint, Mark Golden on Paint.
Utrecht Art Supplies Studio Craft: House Paint vs. Artists' Colors?