Frank Residence, Pittsburgh, Pennsylvania, 1939-1940: Duct and revised coal pocket: section and details (1/2" = 1'-0")

Watercolor and graphite on off-white wove paper

Black ink, gray wash, black crayon and graphite on off-white laid paper

Graphite on off-white wove paper

Watercolor

Black ink on cream wove paper

Watercolor over graphite on off-white wove paper

Watercolor and graphite on cream wove paper

Graphite on paper

Graphite on off-white wove paper

Charcoal and brown ink on cream wove paper, set down to blue-gray card

Black ink on off-white wove paper

Graphite on cream wove paper