It had been a long time since I had used only the mouse to make an illustration, and the truth is that it is not at all efficient or comfortable, especially when sketching. With line art, it's easy because I can use vector strokes, but trying to use the mouse as a pencil is a feat. In the end, it was interesting, and I'm not complaining, but I'll still go back to pencil and paper, hahaha.
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ORIGINAL SKECTH:
PROCESS: