Extremely clever concept from Etsy seller QueInteresante: Label crayon colors with the names of the chemical compounds that produce them

As much as I like this idea, I’m obliged to point out a bit of hand-waving going on with the fine points of spectroscopy, here. One of the crayons, for instance, is apparently labeled “Barium Nitrate Ba(NO3)2 Flame,” which is to say that the crayon is the same color as the flame produced when you burn barium nitrate in air, not that barium nitrate is the pigment used to produce the color in the crayon itself.


Reflectance spectrum of solid barium nitrate, left, versus emission spectrum, right.

This is understandable, really, because the chemical composition of many crayons, even if you ignore the wax binder and just focus on the coloring, is extraordinarily complicated, containing many different pigments carefully blended to achieve just the right color. Even if the formulations weren’t trade secrets, it’d be doubtful if many of them could be fit on a crayon label in a legible typeface. [via adafruit]


Sean Michael Ragan

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c’t – Magazin für Computertechnik, and The Wall Street Journal.

  • hueM

    kind of lame. a majority of synthetic pigments are synthesized with coal tar dyes (aromatic amines). Usually combinations in crayons are non-toxic and do not contain toxic metals or minerals like mercury, bismuth, and yttrium. maybe not the best to teach kids about these gnarly pigments. Have the kids pick up some waldorf crayons with beeswax genuine indigo, madder, and weld. much more interesting than these labels with finite toxic metals.

    • Tony Q. King

      Not for children!
      In the same class as those little magnetic buckyballs.
      Neither should be used inappropriately.

  • Tony Q. King

    Hmm.. must find out how I can incorporate my rapberry pi (smuggled into Canada) with a spectrometer to see how I can catalog these crayons.