Make sure that you use fresh skim milk. Powdered milk or milk that is full or partial fat does not work to make milk paint. Don’t warm the milk, just let it sit out. Warming the milk past 115 degrees Fahrenheit (46 degrees Celsius) breaks down the proteins of milk.
Stop stirring once you have incorporated the vinegar.
Make sure not to stir or to shake the container of milk. This will disturb the formation of the curds.
Try not to get the powder on your hands or eyes. Consider wearing a mask so that you don’t inhale it.
The curds that you separate from the whey are also called quark
After a few minutes of stirring, the curds should have broken down. If they are still lumpy, let the mixture sit for 15-30 minutes.
The mixture should have the consistency of a light cream. If it is thick or sludgy, add water by the tablespoon and stir until it has a lighter consistency.
The cheesecloth will catch any remaining chunks of curd. Dispose of these chunks.
Stirring is especially important if you have let the paint sit. If you are worried that the paint won’t stick to the surface, add a measure of acrylic binder to the milk paint. Follow the instructions on the container to determine how much to add.
Use a bristle brush if you like the look of antiqued finishes where you can see the faint lines of the brush. If you want a more uniform finish, use a foam roller.
Two layers of paint is often enough to coat a surface. If the paint job looks thin or you can still see the surface underneath, wait for the second layer to dry, then apply a third layer.
