Milk paint and chalk paint are decorative finishes that can seem so similar, that telling the differences between them may feel like splitting hairs. Both finishes are often used for creating distressed or antiqued dressers, chairs, tables, doors, and virtually any item that will take paint. Both finishes generally have a matte-like feeling and, in fact, are valued as much for their texture as for their appearance. Unlike latex paint and particularly unlike oil-based paint, both milk paint and chalk paint have little odor and dry exceedingly fast. They are easy to mix and thin. Both milk paint and chalk paint are water-based and have a very low amount of low volatile organic compounds (VOCs). With all of these similarities, are there any differences between milk paints and chalk paints that govern their individual uses? Or are milk paints and chalk paints basically interchangeable?
How Milk Paint and Chalk Paint Differ
At the heart of it, one ingredient—milk—is the main difference between milk paint and chalk paint. Both paints are mineral-based, with calcium carbonate as the chief mineral. Select pigments such as ocher, umber, iron oxide, and lampblack, as well as other minerals and water, comprise the rest of the paints. But milk paint differs because it has that organic ingredient: milk protein. Chalk paint is 100-percent inorganic.
Milk paint comes as a dry powder base with separate dry pigments, all of which must be thoroughly mixed with water. Chalk paint usually ships complete and fully-mixed; before application, the paint must be stirred to redistribute the pigments.
Both milk paint and chalk paint lack that pronounced chemical smell found in latex paint and especially in oil-based paint. However, chalk paint has no smell after it is applied. Milk paint, owing to its caseins, does have a faint smell of fresh-cut grass that lasts for about one hour after application.
Paints have long been based on foodstuffs such as eggs and olive oil, so it makes sense to use milk proteins as a natural binder for paint. Milk paint tends to be used for large furniture and even for broad expanses like walls and ceilings. Since milk paint is usually thinner than chalk paint, it is suitable for further thinning out and for use as a paint wash.
Milk paint lets you create your own unique color by mixing dry pigments into the liquid base paint. If a very low-level sheen is desired, milk paint's matte finish tends to have slightly more of a native sheen than chalk paint's matte finish. Milk paint's lumpiness is due to pigments that have failed to break up with mixing. This can be an advantage if you wish to create a streaky finish. Milk paint can help you achieve the chippy distressed look, as it will flake away with sanding. Some milk paint companies even sell paint specifically for that chippy look. Milk paint is green and eco-friendly, milk paint is naturally non-toxic.
On the other hand, milk paint's consistency tends to be lumpy, so it usually needs to be power-mixed rather than hand-stirred if you want an even finish. Since milk paint is always best when mixed up fresh, this adds an extra step to the painting process. Due to the organic ingredients, most milk paints cannot be saved for more than a day or two, though some milk paints have additives that extend the shelf life to about two weeks. Refrigerating milk paint will help preserve it.
Ability to create unique colors
Matte finish has a native sheen
Can create a chippy, distressed look
Green, eco-friendly, and non-toxic
Needs power mixing vs. hand mixing because of lumpy consistency
Must be mixed up fresh
Short shelf life
Chalk paint has become a favorite decorative finish mainly due to the influence of one person: Annie Sloan. In 1990, Sloan developed the only product that legitimately can be called Chalk Paint. However, other paint companies such as Behr, Kilz, Valspar, and Rust-Oleum manufacture chalk-type paints with similar properties. Chalk paint dries to a very flat, chalky texture, though adding a beeswax coating will give it a lustrous, velvety feeling.
Because chalk paint comes in mixed, liquid form, it only needs to be hand-stirred prior to use. Chalk paint can sometimes require little prep work in the form of sanding or cleaning. While chalk paint is often thought of as an antiquing finish, it can also be used to create a modern, smooth, streak-free texture by sanding down multiple layers with fine grit sandpaper. Chalk paint is completely odor-free, and most chalk paints will be completely dry to the touch within an hour or even less.
Chalk paint's higher build can be an issue if you want to see and feel the underlying texture. If this is the case, thin out the chalk paint. While chalk paint does tend to come in attractive designer colors, it is usually not possible to order custom colors. If you wish to make your own custom color, you will need to mix one chalk paint with another chalk paint rather than mixing dry pigments.
Only requires hand-mixing before use
Can create a smooth and modern texture
Dry to the touch within an hour or less
Higher build leads to inability to feel underlying texture
Not usually possible to customize colors