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

Black and blue marker and black pen on paper

Graphite on paper

Black crayon and graphite on gray prepared antique laid paper

Graphite on ivory wove paper

Graphite on cream wove paper

Graphite on cream wove paper

Black chalk and white gouache on blue antique laid paper faded to gray

Charcoal, chalk, and graphite on paper

Graphite on paper

Graphite on heavy cream wove paper

Watercolor and gouache over graphite on off-white laid paper