Study for the Cupola of the Duomo, Florence

Black ink, charcoal, and watercolor on cream laid paper

Blue marker on paper

Graphite and black and white chalk on gray-brown wove paper

Black crayon on paper

Black chalk and black opaque wash on tan wove paper

Black crayon on paper

Black, pink and brown crayon on paper

Ink on vellum

Black ink on tan wove paper

Pastel

Colored marker and black pen on paper

Graphite on white modern laid paper