Pretty sure that's Golden Ratio. Brought about by artists & scientists. Also describes why one person is attracted to another.
I'd agree with DR809 completely, very good advice. Is it possible to see the render/image? Looks a bit LQ to me but I can't tell whether that's because its sketched or not.
I'd refer you to Papa's Text tutorial as well as what Site has linked.
Papa's Text Tutorial: http://www.gfxvoid.com/forums/showthread.php?t=45209
Helped me out a lot when i was starting.