Making Chalkboards
Don Stephan
A couple times I have made chalkboards, and they never have held chalk as well as school blackboards. The first time several decades ago I used an aerosol can of chalkboard paint, a few years ago I purchased over the Internet a specialty chalkboard pain in pints. I'm using 1/2" diameter large chalk, but can't make a solid chalk line. If using just a portion of the circumference I get a pretty solid line, but a lot of wasted dust, and for a sidewalk sign board a narrow line can't be easily read by passing motorists. If I use the entire diameter, I get a wide but very light chalk line, again one that passing motorists can't easily read.
With the pint of specialty paint I purchased a white 1/4" thick plastic board product that was recommended by the paint manufacturer. Can't remember what I tried with the aerosol an decades ago but probably 1/4" MDF.
Last spring on the recommendation of a neighboring business I tried a Magic Marker like product that I think advertised itself as a liquid chalk I think, but it is recommended for a special very expensive board the manufacturer also sells, and was near impossible to wash off the chalkboard I had made.