its pretty simple you see... you first hold your finger in the screen when drawing, and move your cursor thingy or whatever the hell that square is called in your chromebook (mouse works too) and then you draw and hold and it makes a line, continue to do this perfectly or copy paste different layers to make that perfect line sitting, and then press the t key or the yellow marker logo thingy and you shade in those lines with a low-ish opaciticy color to make it look like that