|Photo from The Creativity Eschange|
It's super easy to do yourself.
- Get a pencil sharpener with the larger hole (the kind you use for Kindergarten pencils)
- Choose an assortment of coloured chalk
- Sharpen the chalk just like a pencil
|Photo from Things That Are Pretty|
I don't recommend this for every project, sometimes you need a precise, thin mark to follow, and sometimes you need something that absolutely can't be removed. I tend to use sharpened chalk the most in my sewing.
A quick Google search tells me that this a common technique for really precise chalkboard writing. I have never thought of that, to be honest.