I’ve been using acrylic paint for a long time and it’s one of my favorite materials. Like all materials, though, it has pros and cons and requires some knowledge of techniques to use it to best effect. Here you’ll find almost everything I’ve learned about this lovely supply over the years: what is acrylic paint, how to use it, what to mix it (or not mix it) with, and what to paint with it.
What is Acrylic Paint?
All paint is made by mixing two things: pigment and medium. In watercolor the medium is gum arabic, in oil paints it’s usually linseed oil, in acrylic paint it’s acrylic polymer. Pigment is what gives paint its color. Until modern times pigments were derived from natural sources: minerals and elements, soil, precious and semi-precious stones, plants, and even animal sources (especially insects). Now there are synthetic pigments created in chemistry labs. These can be more vibrant, and a lot cheaper than natural pigments.
The type of pigment (natural or synthetic) and how much pigment goes into a given amount of acrylic medium may vary depending on whether a particular paint is artist or student grade. Artist grade paints have more pigment, are more resistant to wear over time, and usually, have clearer colors. Student grade paints have a lower density of pigment and often use cheaper synthetic pigments, denoted in color names by the word ‘hue’. So for example ‘cadmium yellow’ might be the color name on an artist grade paint, while the student grade paint might be called ‘cadmium yellow hue’. This indicates that the former is made using cadmium as a pigment, while the latter is made with cheaper synthetic pigments intended to appear as close as possible to true cadmium yellow.
Acrylic Paint’s Superpowers and Shortcomings
Two properties of acrylic paint are most important to know: it is water soluble when wet (or open), and it dries quite quickly. Because it is water soluble acrylic paint is easy to work with and clean off of your tools and work area. But that’s only the case when it’s wet. Once the acrylic paint dries it will be harder to clean up. Pigments absorb readily in porous materials like clothes, wood, paper, etc. So you’ll want to protect those surfaces from when painting.
Acrylic’s quick drying time means you can work in layers without waiting long in between. Because acrylic paint is generally opaque it is also easy to cover any areas you want to change. How opaque a paint is may depend on the grade, brand, or whether it’s mixed with a medium.
Another thing to keep in mind with acrylic paint is that it’s a polymer and when dry it forms a sort of plastic film. You can see this if you spread an amount of acrylic paint on a smooth surface and let it dry. Once it’s completely dry you can peel it off the surface like plastic wrap. This matters because it means acrylic paint will not adhere well to smooth surfaces. You’ll need to use specific mediums, gesso, or some other technique if you want to use acrylics on substrates such as plastic, glass, metal, ceramic, or smooth, non-porous materials.
Mix it Up
One of the most interesting things you can do with acrylic paint is to mix it with mediums to change its properties or texture. There’s a huge variety of mediums. The one you absolutely need for paintings is acrylic (or gel) medium, almost always labeled as gloss, satin, or matte medium on containers. If you want to dilute your acrylics when working on a painting DON’T use water. This will compromise your work. You should also use a varnish to seal your paintings once done.
Other mediums can change the consistency of paint. Modeling paste and heavy gel medium thicken paint. This is great for showing brush strokes or other tool marks on a piece. Pouring medium makes paint runnier for creating dripped and poured effects. Slow dry medium (or retarder) slows down the drying process making it possible to blend colors on the canvas and achieve effects closer to oil paint.
There are also mediums that allow you to use acrylics in airbrushes, or turn them into fabric paint (my personal favorite). There are mediums with sand, tiny glass beads, pumice, iridescent glitter, fibers, anything you can think of. You can also buy powder pigments or fine glitter to add to paints or directly to mediums.
How to Clean Up Acrylic Paint
Acrylic is water soluble when wet. You can easily clean it off brushes, tools, palettes, and containers as long as it’s still wet. Never let ANY paint dry on your brushes. If acrylic paint dries on your containers or tools you can usually peel if off. Acrylic is not easy to wash out of clothes and fabric. If you get acrylic paint on clothes wet the area and spot treat immediately as you would any stain (scrub or brush soap or detergent on the spot). This may not work on all stains as pigments will quickly absorb and stain light-colored fabric.
If the paint has already dried you can dissolve it with rubbing alcohol or acetone. This will dissolve the acrylic medium but pigments may have already permanently stained light colored fabrics, woods, paper, and other porous materials. Rubbing alcohol and acetone are very effective at cleaning acrylic paint from non-porous surfaces if it can’t be peeled after it’s dry.