"To me, pencil drawing is a very emotional, very quick, very abrupt medium... I will perhaps put in a terrific black and press down on the pencil so strongly that the lead will break, in order to emphasize my emotional impact with the object. . . . Pencil is sort of like fencing or shooting. Yet sometimes my hand, almost my fingertips, begins to shiver when I start.”
Andrew Wyeth

http://www.frida-kahlo-foundation.org/links-42.html  
http://www.toulouse-lautrec-foundation.org/links-42.html