The technique of the pen is vastly different from that of any other tool the artists use, and the work done with a pen is consequently very unique. By nature it is a much harsher and a less flexible instrument than either the pencil or the brush, even though pens have come a long way. A pen drawing has a distinct individuality, no matter what kind of a technique is used, fundamentally because of the manner of getting the various tones and shadows, which is different from that in the other mediums generally used.