Poster Paint

Hello all, now I am starting sell my picture to my friends in BimBel Quantum and my family. And now, I am using poster paint, it can help me to color more easily than use crayon. I use a brand faber castell, with the contents of 12 colors. Now, I learn how to mix colour and how to make a special effect. Sometimes, I had a bit of trouble when using the color black. Reasonable as a beginner. And my mum said that I must give signature every picture when I am drawing.