Mark Powell's Vivid Biro Pen Portraits On Antique Envelopes

London based artist Mark Powell has a rather unusual way of practicing the art of drawing. Using antique envelopes as canvases, he draws incredibly vivid portraits of elderly people using only a biro pen. His artistic path is also an unconventional one just as his art.
Mark practiced art in high school and eventually end up being enrolled in university by pure accident. Although his steps have wondered in so many places, he didn't stop drawing and after having seen so many different people from so many different background, he finally settled on this unique signature: biro pen drawings on old envelopes.
(thanks Andrei)