Silverpoint is a Medieval drawing medium rarely practiced by artists today. The technique allows the artist to design with very fine lines of pale-gray color on a suitably prepared surface. While initially a silverpoint drawing resembles a graphite drawing, a drawing in silver left open to the air will begin to tarnish after a few years and the dull gray lines will take on a warm, sepia hue.
Silverpoint has several drawbacks which may have hindered its continual use in the half millennium since the Renaissance: it is a medium geared to careful description rather than overt expression; building up a dark, even gradation takes time and patience, and even then, it takes great control to create contrast in the finished work. Also, once applied, the silver line cannot be easily erased without disturbing the surface and preventing the perfect adhesion of new lines.
My preferred materials and techniques haven't changed much since I learned silverpoint from my drawing professor, Chuck Schmidt, at Tyler School of Art in Philadelphia back in the 1980's. I use hot press 140lb. watercolor paper, and a simple stylus made from silver wire held in a mechanical lead holder. For a ground, I use white casein thinned with water, and I tint the liquid ground with watercolor.
An excellent source for information about silverpoint, as well as links to other artists and resources can be found at SilverpointWeb.com.