Dealing with Mold on a Watercolor Palette

A simple method for eliminating and controlling mold on your watercolor palette.

A couple of FAQs about this video:

Does rubbing alcohol hurt your watercolor paints?

No. (Would I tell you to do this if it did?)

However, if you start painting when you still have alcohol in your paint wells, it can affect the behavior of the wash. So just give it a few minutes to let it all evaporate before you start painting. (BTW, some people take advantage of this effect to create little spots by spritzing or dropping alcohol into a wet wash. I don’t care for this effect, but you can find plenty of other people demonstrating it. Or you can just try it yourself and see what you think.)

I heard that you won’t get mold if you use distilled water. True?

Sorry, nope.

Some people who use distilled water never get mold. And some people who use tap water never get mold.

These molds are common soil organisms. They don’t get into your paints through your water (unless maybe you got it from a puddle). Mold spores drift along on dust particles, so if these molds grow in the soil where you live, they’re going to be floating around in the air, too. If you live in an arid climate, you may have few mold spores floating around, but if there is any irrigated landscaping or agriculture, you can find them in the air even in arid locations.

Whether you wind up with mold growing on your palette is basically a combination of how much mold lives in your local soil, how easily outside dust can float into your studio (or palette), and whether you let your paints dry out completely or keep them moist.

I like to work with moist, tube-consistency paint, so I do sometimes find mold. Usually on a palette that I haven’t used in months—the very best way to prevent it is to paint a lot!

You can generally avoid mold by allowing your palette to dry out completely every time you finish painting. I don’t care for working with completely dry paint, so I accept the trade-off that there could possibly be mold on my palette someday, but even so, it’s not an everyday occurrence. I’ve been painting in watercolor over 20 years, and I think I’ve had mold on my palette 4 or 5 times.

Many people DO just decide to let their paints dry out so they don’t have to worry about mold. Since I know I can use this rubbing alcohol trick to deal with mold if it happens, I keep my paints moist so I have the working consistency I like. You have to decide what matters most to you.

I have also lived in some locations where there were a lot of airborne mold spores. In that situation, I do sometimes just spritz my palette with rubbing alcohol as a preventative, especially if I’ve been painting outdoors.