Painters rely on their paints, and it is important to take care of those valuable tubes at all times. While oil paints can be more accepting of temperature fluctuations, acrylics are not.
If you work with acrylic paints, you will need to pay attention to the temperatures in which they are stored. Many acrylics will become unusable if they freeze and thaw multiple times. It is best to store them in a location that you would be comfortable living in.
It is important to remember that acrylic paints are water-based pigments, which makes them prone to freezing. This can damage the quality of the paint over time.
Many acrylic manufacturers take into account that their paints may freeze and thaw during shipping. Some even admit to factoring 10 freeze-thaw sessions into their paint formulas. However, as the end user, you do not know how many times a tube of acrylic has been frozen before you purchased it.
When it comes to acrylic paints, it is best to err on the side of caution and keep your paints at a semi-even temperature. This also extends to the temperature of the environment that you are painting in and storing your finished pieces.
If your studio has extremes in hot and cold temperatures, such as a room in the attic, basement, or garage, you will want to do your best to regulate the temperature. Many acrylic manufacturers recommend temperatures of 60–75 F (15–24 Celsius) for storage and application, and anything below 45 F (7.2 Celsius) is certainly not recommended. Check with the manufacturer of your paints for their specific recommendations.
It is also important to remember that finished acrylic paintings can crack if exposed to freezing temperatures during storage or shipping.
Tip: If you have to ship an acrylic painting in the winter, it is worth the investment to ensure it is transported via a temperature-controlled truck. Should you need to ship a rolled acrylic painting, allow it to reach room temperature before rolling it to prevent cracking (and advise the recipient of the same before unrolling).
The same advice for acrylics applies to all paint mediums that are water-based, and that includes water-soluble oils. Traditional oil paints, by comparison, have a base of linseed oil, which freezes below zero.
If your acrylic paints do freeze, you may not notice a difference the first few times. Yet, you are pushing your luck and may notice the paint begin to change. If it doesn't change the first time, it may the second time or the third.
In the best-case scenario, the water and pigment in the paint may begin to separate. This can often be fixed with extra mixing: shake, stir, or work it with a palette knife until the elements become one again.
If the paint has been exposed to freezing temperatures for too long or frozen and thawed too many times, it may reach the consistency of cottage cheese. This lumpy, runny mess may also be worked out, but it may cause problems during application or with the color saturation and longevity of the finished painting.
Should your acrylics become stringy or gummy, you can count those tubes out. Replace those colors.
All of these problems can be prevented with a little planning and proper storage. If you pay attention to where you store your paints, you should not have an issue, and your acrylics will have a very long shelf life.
A sound piece of advice is to store your acrylics at a temperature that you would be comfortable in. That is typically in the 60–75 F (15–24 Celsius) range previously mentioned.
It is tempting, particularly if you take a break from painting for a year or more, to store paints in the basement or garage. Unless you live in a temperate climate, this is not advisable because extremes in temperatures are common in these parts of the house.
Instead, consider packing unused paints into a shoe box or compact container and placing them in a closet or on a shelf inside the temperature-controlled part of your home. They really will not take up much space, and you can store other materials like brushes, empty canvas, and boards in the basement or garage; just protect your paint!
Tip: Don't forget about your paints during a move in the winter months. If you have to move houses or studios in the winter, place your acrylics inside the warm car so they are not exposed to extreme temperatures while in transport.
Painters who do live in very cold climates or have issues regulating the temperature in their studio may want to consider switching to oils. This will alleviate many of the headaches associated with extreme temperatures.