Untitled (notes on planets and bleed-through of previous page, left page); Untitled (calculations on back endpaper, right page)

Colored marker on paper

Purple chalk on cream modern laid paper

Graphite on off-white wove paper

parchment

Brown ink over graphite with touches of red chalk on cream antique laid paper, framing lines in graphite, laid down on cream antique laid paper

Graphite on cream wove paper

Graphite on off-white wove paper

Watercolor and black ink over traces of graphite on off-white antique laid paper, adhered to cream antique laid paper

Graphite on white wove paper

Charcoal and graphite on illustration board

Red and white chalk on blue-gray wove paper

Colored pencil on brown wove paper