If you want to know if Acrylic paint expires, the short answer is no, but acrylics do tend to run the risk of developing mold and drying out. Acrylic paint is a synthetic-based material so it can’t technically “expire” like some other art products. You should know however that Acrylics are infamous for drying out very fast.
It really depends on the quality of the paint you purchase. I always recommend buying “artist quality acrylics, not “student quality” paints. This Arteza Acrylic Paint Set, is the one I personally use. You can buy mediums to assist with the wetness of the paint such as acrylic wetting agents and mixers which can help resuscitate dried paint.
An easy way to tell if your acrylic paint has gone bad is to smell them. They often develop a sour, mildew smell when they’re past their prime. They may still be usable, but you can tell they’re time is almost out when they start to smell sour and off.
Shelf life: 2-5 years, until they start to smell sour or dry. Look out for: Mold and an stinky milk smell.
How Long Does Acrylic Paint Last Once Opened?
Acrylic paint has a shelf life of about 10+ years when stored correctly. If it’s unopened after 10 years, it’s probably still usable. Opened and unopened cans of paint last for years when stored correctly. I usually finish a tube of paint within a month, but I have had tubes and cans that have sat in my garage for years, and when I opened them they just required a little mixing, or a wetting agent that re hydrated the paint.
Keep in mind that once you begin to use the paint, whether you have tubes or plastic jars with screw-on lids, air gradually flows into these containers, evaporating liquid contents and drying out the acrylic paint.
By simply regularly opening and closing the container, paint may dry out around tube caps or screw-on lids. You may need to scoop out and discard the dried paint globules. Eventually, further drying may change the physical properties of the acrylic paint, making it impossible to work with.
Why Does Acrylic Paint Go Bad?
As with any other liquid, ambient temperatures can have a significant effect on acrylic paint. Acrylic paints are made up of a number of different materials including pigment and a polymer emulsion. These materials are susceptible to extreme temperatures. Did you know that one of the main reasons acrylic paints were created, was to get a paint that dries more quickly?
When acrylic paint loses too much of the water and other liquids that keep it pliable, it turns into a solid. This is especially problematic with acrylic paints because when dried and cured, these paints take on a plastic-like texture and become water resistant, which makes reusing them impossible. I always recommend using a mixer or wetting agents to keep your paint from fully drying and making it completely useless.
Acrylic paints are liquids that are an mixture of multiple substances. When exposed to cold temperatures for an extended period of time, the chemicals in acrylic paints have a tendency to separate.
This separation always happens because the cold affects the contents of the acrylic paint. In the case of extreme cold, the different liquids in the acrylic paint can freeze. Since every liquid freezes at a different rate, the materials that freeze first push out the other materials that don’t freeze as fast. This separation due to freezing is harder to see until the paint has had a chance to thaw.
Mold and Mildew
Mold and mildew are the bane of every homeowner. But did you know that acrylic paints can grow mold and mildew also? Mold and mildew are frequently associated with warm humid areas where foreign contaminates are present.
With paint, mold and mildew can grow when paint is exposed to unfiltered air or contaminated water. You can have mold in your garage without even knowing, making your Acrylics susceptible to mold.
Best Places to Store Acrylic Paint
The best place to store your Acrylic paint is in an air tight plastic container. Apart from that, I store mine in the garage since it’s neither cold or too hot. If you have a decent temperature garage, I would store them in there, or in a big air tight plastic container perhaps in your closet.
Always remember not to store your acrylics where it’s too hot or too cold, as this will ruin your paints. Depending on the amount of paints that you have, it’s convenient to keep them in a plastic container in your closet or somewhere in your home. If you have a huge collection of paints and supplies, the garage is always most convenient.
To store them, make sure there isn’t a leak (such as a pinhole) in the tube, as this will ruin the paint and cause it to dry out. If you notice a leak, a small piece of duct tape can prevent air from entering the tube and ruining the paint.
To prepare acrylic paints for storage, wipe away any excess paint before storing the tubes, as this paint will dry out and crust over, making it hard to open the tubes again.
For paintbrushes, the most important thing to remember is to put them away in good, clean condition. Good paintbrushes are an investment and should be washed and dried carefully right after each use. Prior to long-term storage, use a brush cleaner rather than just washing the paintbrushes the way you usually do, with water or paint thinner.
Paintbrushes should be stored away from leaky paint tubes. Most paintbrushes will store well for many years as long as they are in good condition and impeccably clean when they’re put away. I’ve had my set of paintbrushes for over 3 years now and I keep them in a good, clean condition.
Best Temperature to Store Acrylic Paint
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 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.
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.
When it comes to acrylic paints, it is best to be 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 extreme 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. Check with the manufacturer of your paints for their specific recommendations.
How to Restore Dried or Hard Acrylic Paint
The best way to restore or “re hydrate” your Acrylic paints are with wetting agents or mixers. These products help restore your acrylic paint to a desired consistency again. You can also try some of the steps below as alternatives.
- Add water, and dip your paintbrush in a cup of clean water and then gently tap the water from your brush onto the paint. Carefully work the water into the paint using your brush, adding more water if necessary, until the paint becomes more liquid.
- Mix the hard paint with a palette knife. Add a bit of water to the paint and then mix it together with a palette knife. You may have to use a grinding motion a few times for the water to mix in with the paint. You can also use a palette knife if you add an acrylic additive to help with the process.
- As I mentioned above, if the acrylic paint has fully dried or hardened, add a product like Flow-Aid Fluid Additive or Acrylic Flow Improver. Squeeze out a small amount of the additive and gently mix it with your paint until the paint reaches your desired consistency.