Making Sidewalk Chalk

I’ve been wanting to do this for awhile…and now FINALLY. Sidewalk chalk. Homemade. And from legal materials.

What are the key ingredients? Two. “Plaster of Paris” (aka “plaster”) and tempera paint. That’s it. Oh, and you’ll need molds. Paper towel tubes work great. But first, you’d need to line them with wax paper. Kinda like this…

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…only you don’t have to get all particular. Really. I happen to cut the tube length-wise and use spray mount to attach the wax paper to the tube’s interior. That way I could control the diameter of the mold, by overlapping the edge, as opposed to being stuck with a set size. See?…

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…overlapping edge. Smaller diameter. Next, simply following the directions on whatever stock of plaster you purchase ($3). Note that if the directions say “1 lb. of plaster …” that 1lb. amounts to 16 ounces or 2 cups. I mixed half the recommended amount -and that yielded 2 pieces of chalk. Anyhow, once the plaster was mixed I simply added tempera paint.

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To create a strong pink I had to add lotz of red to the pink paint to richen the value.

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After a thoroughly mixing I poured it into the tubes. For orange I had to mix and add a stronger pigment as the orange straight from the bottle was weak. Red + yellow, baby. Only more red than usual.

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Typically you’ll find 1-part red to 3-parts yellow works. For this I did 1-part red to 2-part yellow. But, seriously, moving on…

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…same process as above. Mix ‘n pour.

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In just under an hour I was able to release the mold…

ud_110514b_05…and see the results. Overall this method makes a noticeable softer chalk with, due to pigment control, deeper colors.

ud_110514b_06This was the test. Next, I’m planning to make the usual batch of colors…plus a version of white that contains glitter.

-I mentioned these weren’t for me, right? You knew that I hope. Cause what would I do with sidewalk chalk?? Like, draw?! -Psssh! Yeahright.

  • spaceman

    DUH. Why have I never seen glitter sidewalk chalk? There’s a LOT of sidewalk here in SF that could use some color… just sayin’….

  • spaceman

    Have you tried any lighter colors, like yellow? I wonder if the tempura will have enough pigment to color the plaster without diluting the mix too much to harden. If so, I bet that dry artist’s paint pigment would work.

  • @spaceman!…
    I’m thinking about using food coloring as opposed to tempura paint. Might work. Yellow and other lighter colors will be tricky -but food coloring is like Indian ink in terms of color density. If that doesn’t work then I’m heading towards powders. Which are actually ideally since adding liquid tempura to the plaster dilutes the plaster alil.

  • Kevin! this is so awesome! I want to try with with my nephew now, I’ll be the coolest aunt around! and I love that you took the chalk and made a crazy long hop scotch! so fun!

    Cheers!

  • @Phaedra
    Thank you! Oh, and I’d swear you have the most amazing name.

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