Street artist Sam3 is internationally known for his silhouette paintings on building walls seen in Lisbon, Barcelona and beyond. In 2013, he has continued to use his signature black paint for eye-catching murals, an example is the optical illusion shown above. Sam3 has also explored white paint graffiti, coloring parts of wood fences and leaving other portions blank to form a face or angel, a technique similar to figure-ground perception.

Photos © Henrik Haven

Via This Isn't Happiness