What is wax bloom, and can it be banished?
If you use wax-based colored pencils or wax pastels and artist crayons, you’re probably familiar with wax bloom, that cloudy, grayish or whitish crystalline film that forms on the artwork.
Also called efflorescence, wax bloom is one of the few unpleasant things about coloring with colored pencils. It can form over a period days, weeks, or even years. Humidity is one contributor; the more humidity, the more likely you are to get wax bloom. It’s also more likely to happen with heavy layers of dark colors that are topped off by a thick burnishing layer.
Wax, used as a binder, oxidizes over time and rises to the top. Wax bloom not only affects coloring books; encaustic art some ancient art that uses beeswax are also afflicted.
Getting rid of wax bloom
Wax bloom is not the end of the world. With certain steps, it can be ameliorated or eradicated. To get rid of it, many colorists simply wipe it carefully with a cloth made of something soft such as cotton; an old cotton t-shirt will work. However, you must wipe very carefully, because cloth can smear pigment. The cloth method doesn’t work permanently; the bloom will return.
If you see wax bloom sprouting up after you’ve framed your art behind glass, it’s fine to remove the glass and spray fixative.
Nothing is 100% guaranteed to be effective against wax bloom. If you truly want to avoid it, then skip the wax-based pencils and used oil-based ones such as Polychromos or Luminance. If you really prefer wax-based, try to not use thick, heavy layering. Some non-primarily-wax pencils still have some wax, but that should not be a problem. (see best colored pencils)
Understanding how the binders and chemicals in art supplies will go a long way in preserving your art. Also good to have is the ability to stay calm in case you do pick up your prized piece and see a gray film. Relax, relax, it’s only wax.