Got Milk Paint?
There is renewed interest in an ancient decorator's tool that owes its existence to cows. Yes, that's right, cows. Long before pre-mixed paint in a can was available, people made their own paint from a combination of natural ingredients: milk protein (casein), lime, clay and pigment. From the tombs of ancient Egypt to the farms of North America, milk paint created a durable finish that could last for hundreds, even thousands of years. Although the popularity of milk paint diminished with the introduction of manufactured paint in the 1940s, milk paint has remained the essential choice for farmhouse furniture restorers. Today, more and more homeowners are starting to see the benefits and possibilities of milk paint.
The durable finish of milk paint is mainly due to the casein content. Casein is the ingredient in milk that creates the tough, somewhat rubbery texture of cheese. Historically, casein was collected through the process of curdling, which separates the casein from the milk. When the casein was dry it was crushed into a fine powder. It is because of this ingredient that milk paint binds to wood and other surfaces. The addition of lime to milk paint makes it possible to mix the dry ingredients into water. The result is a product that rivals, and sometimes surpasses, modern paint depending on the application.
Another benefit of milk paint is its low toxicity. Unlike pre-mixed paints, milk paint does not contain solvents. The solvents in standard paint release volatile organic compounds into the air for weeks or even months. Some of these compounds are toxic and carcinogenic. Solvents are used to keep the paint liquid in the can. Solvents slowly evaporate when the paint is applied to a wall or other surface. Because milk paint is sold in dry powdered form, there is no need for solvents. It is advisable, however, to wear a dust mask when handling and mixing the paint with water. There is a faint, milky odour when the paint is wet but it dissipates as it dries.
Milk paint also contains natural low-toxicity pigments. The earth tones of milk paint are created with pigments such as yellow ochre, brick, iron oxide and charcoal. Milk paint is strongly associated with farm living; common paint names include barn red, bayberry, pumpkin and mustard. Consumers are not likely to find fuchsia or lime green in the product choices although it is possible to mix paints to create new colours. To make pastels, simply mix white into the coloured paint. When mixing together two colours, be sure to use the same brand; the ratio of casein, lime, clay and pigment may vary from manufacturer to manufacturer giving an uneven result.
Although milk paint is slightly more expensive than regular paint, a person can mix up only the amount of paint they require. No more paint left in a can to separate and dry out! The only negative aspect to mixing is removing lumps. To make the process easier, and to create a smooth, lump-free paint, use an electric blender. Be sure to wash the blender in hot, soapy water immediately afterwards to ensure that the paint does not dry on the beaters. Prepared milk paint may be stored in the refrigerator for weeks. Dry paint powder will last for years when stored in a tightly sealed glass container.
Coverage is another benefit of milk paint. Because casein binds so well with wood and other porous surfaces, there is no need to apply primer before painting. The first coat of milk paint acts as a primer and should always be applied in the direction of the grain. Sufficient drying time should be allowed between coats. Milk paint is semi-opaque but additional coats of paint can be applied to produce more opaque coverage. This is especially important when it's preferable to allow the grain of the wood to show through. The paint can be applied in thin layers to work up the colour to the desired intensity. For very smooth surfaces, a bonding product such as Extra Bond may be required to help the paint adhere properly.
The flat finish of milk paint makes it unique and highly prized by some woodworkers. Even pre-mixed 'flat' finish latex paint cannot match the subdued finish of milk paint. This is perfect for projects such as restoring antique furniture. To make the piece look even older, the finish can be distressed with sandpaper or crackle medium can be applied. Crackle medium dries to produce fine cracks that resemble old paint. For projects that require more lustre, add a layer varnish or a coat of liquid beeswax. Beeswax is a non-toxic product that has been used to seal and protect milk paint furniture for years.
Although milk paint may not be a good choice for walls that need a bit of sheen, it is an excellent choice for painting stencils on hardwood floors, molding, and some types of furniture. Milk paint offers the convenience of mixing small batches and it is a very low toxicity product. It can be found at craft stores and specialty paint stores. Maybe it's time that you discovered what the ancient Egyptians knew by adding some milk to your decorator's palette!