Bahner Residence, Berlin, Klein-Machnow, 1933: Drainage system: detail sketches

Ink and colored crayons ; colored crayons on paper

Colored marker on paper

Watercolor and black ink on gray silk mounted on gray card

Black crayon on paper

Black marker on paper

Colored marker on paper

Watercolor and charcoal on off-white wove paper

Black marker and adhesive on paper

Colored marker and blue pen on paper

Graphite on paper

Graphite on paper

Black marker on paper