1. Draw the blackboard with chalk (pencils can't be seen clearly without pencils)

2. Just use gouache pigment, and you can add water to color it, but you can't make it too thin. There are three primary colors (magenta, lemon yellow and blue), and these three colors can be mixed with many colors; Yellow+blue (5 parts each) = green; Yellow+red (5% each) = orange, etc.,,, and it is necessary to buy more colors: white, purple, brown, etc.

3. You can wipe off the wrong painting with a wet towel.

4. If you use a pen, you'd better use a set. The number can be single number 1, 3, 5, 7, 9 or even number 2, 4, 6, 8, 1. Use a wool pen to draw well, and the brush pen is flat.

5, gouache pigment can cover,,,