Customizable chalk box with inset

I recently heard about and purchased what is supposed to be the world's best black baord chalk. It came in a crumbled cardboard package and I supposed that someone must have already created a box for chalk sticks. And yes, there was, but ...

A fully open box on the inside will only support the chalk if it is full - if one piece of chalk is written down, the rest will start to rattle. So I decided to improve the design by adding internal compartments supporting one piece of chalk each.

I also included a snap-lock for the lid.