He employed both a sharp-nibbed pen of some kind, and a broad flexible reed, according to the exigencies of his subject or the temper of his mood.

The chalk was either red or black, the former being softer than the latter.

I cannot remember any instances of those chiaroscuro washes which Raffaello handled in so masterly a manner, although Michelangelo frequently combined bistre shading with pen outlines.

In like manner he does not seem to have favoured the metal point upon prepared paper, with which Lionardo produced unrivalled masterpieces.

Some drawings, where the yellow outline bites into a parchment paper, blistering at the edges, suggest a rusty metal in the instrument.