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I've encountered lots of chalkboards through my career, and they vary widely in quality. Some write smoothly and erase cleanly; for others, the chalk squeaks and the eraser just smears.

I assume there are differences in the materials they use, the construction techniques, how the surface is prepared or treated, and so on. But I'm clueless as to what these differences might be, and how they affect the quality. If I'm looking for a "good" one, what questions should I ask?

(Academics are one of the few groups these days that use chalkboards on a regular basis, so I hope this question is suitable for this site. Please note that I'm not asking for specific product recommendations, just general information.)

  • 9
    In my opinion: the best chalkboard is a whiteboard! – F'x Sep 10 '13 at 18:54
  • 7
    @F'x: Should we step outside to settle this? ;-) Actually, I could ask the very same question about whiteboards. – Nate Eldredge Sep 10 '13 at 19:52
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    In my opinion: The best whiteboard is a chalkboard! – JeffE Sep 10 '13 at 20:42
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    There was a question What's so great about blackboards? on mathoverflow. – scaaahu Sep 13 '13 at 4:49
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    "If I'm looking for a good one, what questions should I ask?" Hmmm... Why don't you just try it? If you can write and dry-erase without trouble 10 times using both white and color chalk, it should last forever. If not, it won't work regardless of anything else. Just bring some nasty chalk for experiments (especially the color one). – fedja Sep 14 '13 at 2:56
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The good chalkboards appear to be made of porcelain enamel fused to a steel core. See this site for more details on the manufacturing process. As JeffE mentioned in a comment on another answer, cheaper chalkboards are made by painting wood or chipboard with a special chalkboard paint. Although these are good for crafts, they are NOT the kind you want to have in a classroom. They have to be primed with chalk before the first use and after being cleaned with a damp cloth. Also they will often have to be given another coat of paint after being used for a while.

For non-squeak writing, break long pieces of chalk in half--this will usually take care of the problem! I have noticed that regular, i.e. daily, sponging with an all-purpose cleaning solution also helps to prevent smearing while writing/erasing.

  • Are these chalk boards made of porcelain enamel cheaper as compared to wooden chalkboard? Can schools and other educational institutions be able to afford it? – Sweet72 Sep 13 '13 at 20:13
  • Although I don't know exactly what the price range would be for the porcelain enamel versus the wooden chalkboards, the wooden boards are usually cheaper--and they act like it! Can schools afford porcelain enamel? I guess that depends on just how limited your budget is, but they shouldn't be prohibitively expensive. They might be hard to find, though. Whiteboards are taking over... – J. Zimmerman Sep 13 '13 at 20:54
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Just a partial answer, since I am not discussing materials and building techniques but only giving a couple of tips.

Chalk squeaking should depend on its length; break it into two parts to avoid it. Not sure if this has been studied rigorously, but it seems to work in my experience.

As for erasing, I am personally a fan of using a damp towel rather than dry-erasing. It takes some more work and preparation, but the results are much better.

  • 1
    Doesn't damp erasing remove the dry foundation of chalk, and thus require the board be re-finished with chalk? – Jonathan Landrum Sep 10 '13 at 20:44
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    Some cheaper chalkboards are really just painted wood (or chipboard); erasing these with water is a bad idea. Good chalkboards don't have this problem. – JeffE Sep 10 '13 at 20:49
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    So are good boards made of slate or something similar? I suppose I've never used a good board. – Jonathan Landrum Sep 10 '13 at 21:20
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The best chalkboard, if you can afford it, is slate. It is the combination of grain consistency and durability that allows the consistent accretion of chalk on the surface of the board. The only reason it is not used is that it is prohibitively expensive and either heavy or fragile, depending on the depth of the slate. I suppose this could be improved with a non-flexible backing.

  • 2
    Certainly the best chalkboards I've ever used have been slate. Dark background, high contrast (even with colored chalks), reliable surface and good erasing. Now if only I didn't end up with chalk dust all over everything. But they are expensive. – dmckee Sep 15 '13 at 6:19
  • @dmckee Do you have any brands? – Al Jebr Oct 8 '16 at 17:51
  • @AlJebr No. I'd search for blackboards and then read to find out who can actually deliver slate. Or the porcelain mentioned above though I have never used those. – dmckee Oct 8 '16 at 18:37

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