What exactly is acrylic paint?
A Brief History
Acrylic paint is still a baby compared to oil and watercolor paint. It was invented in the 1940s for the purpose of painting homes. It was very durable and withstood differing temperatures on the inside and outside of homes. They were also very inexpensive to make and could be sold at affordable prices and in greater quantities. It was not until the 1950s that acrylic paint was marketed as a fine art material for artists.
Acrylic paint is unique in that it uses a binder of acrylic (go figure, huh?). To be more specific it is an acrylic polymer emulsion. To keep it simple for those of us who are not chemists, acrylic is a type of plastic. The liquid, acrylic plastic is mixed with the pigment (color powder). Once it leaves paint tube or bottle, the water in the paint evaporates leaving the colored plastic to harden. This why if you paint with very thick brushstrokes, it will feel like very soft plastic once it is dried. The plasticity of acrylic paint makes it very easy to apply to a myriad of surfaces. It can even act as a sealant of certain materials if you buy the right kind. That being said…
What is the difference between thinner acrylic paint and thicker acrylic paint?
As seen in the diagram in the post “Cheap vs. Expensive Paint”, the pigment and the binder are typically what causes the price range of paints to differ. In the case of acrylic paints, the thinner the paint, the less pigment and acrylic polymer are actually in the bottle. The water and other fillers allow for the liquidy texture and (since water is cheap) the drop in price. The high water content also allows for the paint to dry very quickly since water evaporates quickly.
Thick acrylic paints have a much higher quantity of acrylic polymer. Cheaper, thick paint is usually has a higher acrylic polymer content, but a lower pigment content. Acrylic itself is usually a clear substance so the less pigment, the more transparent the paint will be. This means you may need to paint several layers to cover up a previous color. It takes a lot of pigment to make cheaper paints opaque. This can be an advantage in some circumstances and a disadvantage in others.
(TIP!) Transparent means you can see through it. Opaque means that you cannot see through it.
I know that this is a lot of “lecturing” but it is good to have context on why the paint you buy may be acting a certain way. This also helps us use whatever paints we have laying around to achieve the results we want. This was a very basic overview of what acrylic paints are before one jumps into acrylic painting without a paddle.
Don’t forget to tune in over the next few days to learn how to use different kinds of acrylic paints. The paints we will be using range from liquidy craft paints and the thicker, student grade acrylic paints. Both are very affordable and easy to adjust to.