Pastels are messy; there’s no way around it. The pigment creates dust and easily migrates to other surrounding surfaces. Just as a variety of wet pigments produce gray (or mud) when over-mixed, so too does the pastel dust. Since I don’t appreciate the deception of a pastel stick appearing one color and ending up another, I’ve developed practices that keep my sticks as clean as possible.
The two biggest factors involved in this are one, the storage/carrying box, and two, our hands. If a pastel storage container allows for movement, the sticks will inevitably bump into each other, creating contamination. The more stable your pastel case, the cleaner the contents will be. This is another reason for segregating your colors and values into close relationships. With the variety of travel pastel boxes available, it’s easy to find a strong case capable of sandwiching your pastel sticks securely, providing a minimum of movement when transported. Another storage method is plastic containers with airtight lids. Fill these with a moderate amount of rice or corn meal and place the individual sticks in the container. The grains act as a cushion and natural cleaning agent. This is also employed for cleaning pastels that become contaminated. Place them in the container with the grain and gently shake the contents. When you remove the sticks, they’ll be clean.
Since I use a travel pastel case for my pastel palette (click here to refer to my previous blog on my palette), I experience little migration of pigment, meaning infrequent cleaning. A useful method, short of removing all the individual sticks, is to place a window screen (available at most hardware stores) over the open case and gently vacuum (see photo). This pulls the loose dust up and out of the case, helping to keep the contents fresh and bright. Make sure the vacuum has a micro-filter and doesn’t blow the fine pigment dust out the exhaust. Airborne pigment is the major health concern for pastel artists, so use caution.
Another useful habit is to keep a Viva-brand paper towel in your non-painting hand. When finished with an individual stick, tap it against the towel (gently cleaning its surface) before placing it back in the palette. Then wipe your hand on the towel before picking up the next stick. This diminishes cross-contamination from your hand, keeping the sticks clean.
By utilizing these two procedures, I find it necessary to remove all the contents of the pastel box only once a year for a thorough cleaning. And I have the added benefit of knowing what the pastel stick really looks like; no wolves in sheep clothing for me!