With a 10% mixture of the scallop shells, the crystals in the shell powder work as a cement holding the chalk together better, and the new recipe is win-win since scallop farmers have a hard time disposing of the shells, whereas now there’s a practical use for them. And it seems the new recipe also allows for considerably brighter colors compared to the desaturated, washed out tones we used when I was in school. You kids and your fancy colors!
rikagaku.co.jp - ???
