Spanish artist Juan Francisco Casas creates photorealistic monochrome sketches using only a humble BIC ballpoint pen. Some of these stunning pictures measure up to 10 feet in height.

Casas reproduces art from photographs he takes with his camera. He can use up to four 14p ballpoint pens for a canvas and take two weeks to complete. The only drawback is that he can't erase any errors. He said: "Mistakes are the main problem. It's better if I make them at the beginning."

[via Oddity Central]