Luis Seven Martins is a Brazilian artist who tried many techniques and finally created his unique approach by using china ink, latex, pastel and acrylic.  It is not just the technique that L7matrix experimented with. He also came to a unique style through his experimentation – namely, he combines geometrical elements and very stylized color puzzles with realism attained by elaborated details (text from http://l7mstreetart.com/about/).