Denis Zilber Drawings

People have made rock and cave drawings since prehistoric times. By the 12th-13th centuries AD, monks were preparing illuminated manuscripts on vellum or parchment in monasteries throughout Europe were using lead styli to draw lines for their writings and for the outlines for their illuminations. Soon artists generally were using silver to make drawings and underdrawings. Initially they used and re-used wooden tablets with prepared ground for these drawings. When paper became generally available from the 14th century onwards, artists' drawings, both preparatory studies and finished works, became increasingly common.
Shading is the technique of varying the tonal values on the paper to represent the shade of the material as well as the placement of the shadows. Careful attention to reflected light, shadows, and highlights can result in a very realistic rendition of the image.