If you’re using water to thin your acrylics while you’re creating that masterpiece, you could come off your canvas before it’s worth thousands of dollars. In fact, if he is 30 years old, he could start fading before he hits 50! If you’re wondering why you shouldn’t use water to thin a water-based paint, let’s see why.

Not enough artists, and especially emerging artists, realize that adding too much water to acrylic paints breaks down the binder (some refer to it as the vehicle) that holds the pigment together. In acrylic paint, that binder is polymer. Polymer is essentially a liquid plastic compound that is made up of millions of small molecules that are arranged in repeating patterns. These repeating patterns of smaller molecules form larger molecules. It is this structure that acts to bind the pigment in the form of paint. When water is used to thin acrylic paint, these molecules become widely dispersed by suspending the pigment molecules in water and separating them from the polymer molecules. By losing this bond to the polymer molecules, the pigment becomes what is known as “unbound” since water has virtually no ability to bind the pigment molecules. Think of the polymer molecules as forming a kind of glue that holds the pigment to the surface. When this glue, known as a polymer, is diluted with water, it loses its strength to adhere. When the pigment in paint is left loose, over time it will pull away from the surface it was applied to (usually canvas) and begin to flake off. How well the surface is prepared can also influence how well the paint adheres, but even the best prepared surface cannot overcome the damage that excess water mixed with acrylics causes on its adhesion properties.

Diluting your acrylic paint with any of several polymeric mediums allows the pigment to adhere to the surface as the medium dries forming a very solid structure to hold the pigment. If you prefer more of a washed out, watercolor-like effect, for example, to tone down your white canvas, then airbrush medium works great. It can have the consistency of skim milk and works like water as a thinning agent, but it enhances rather than diminishes the paint’s bond to the surface. Other polymer mediums can perform any number of tasks to change the application and body of your acrylics producing very interesting effects. For example, you can extend the drying time of your paint so you can work on it from hours to days; you can expand the colors; increase the flexibility of the dried paint skin; increase translucency or even shape the surface or crack it when it dries. Your painting can also be enhanced for frosting techniques by using the appropriate polymer medium, which can add a matte, satin, or gloss finish depending on the medium you choose. Another important attribute about water is that the UV resistance of your paint can also be improved by mixing it with polymers.

So try the multitude of polymeric mediums on the market to improve the workability, flexibility, and longevity of your acrylics. Use less water. And have fun exploring the creative potential of the many gels, pastes, and other polymeric mediums you can find at better quality art supply stores, a place where you can find a live person to answer your questions and help you solve technical challenges. with your art supplies.