Albrecht Dürer's "Hands of an Apostle". I scanned this from the same 1958 portfolio that had Crivelli's work. Note how this was done entirely in line - there was no recourse for shading or blending. This allowed for the intricate details to be so perfect - if you look close you can even see the ridges typical in the skin of a hand. Overall a beautiful piece and very well done.
