Generally, two boxes of advertising colors are used, if you are drawing a blackboard. It is best not to add water when coloring, but to use a brush head to make the mechanism well. If you need something more delicate, buy Mary's tubular pigment, five yuan a tube. This has the advantage of bright colors, but it is difficult to replace.

Of course, if you need a hard texture, chalk is better, easy to outline, and create a three-dimensional effect. . . . The disadvantage is that it is easy to fade and blur. . . .

Actually, it's not that hard. . . . If you check this box, draw wool with chalk and tighten it like cotton, it will be straighter and faster.