Mehretu creates large acrylic works that then are overlaid with pencil, pen and ink (and sometimes more paint). They are often abstract but are equally likely to have architectural and figurative elements. These pieces are a little different.
Myriads, Only By Dark is a four panel aquatint and spit bite (spit bite is the painting of acid onto the aquatint ground of a plate). The untitled piece is watercolor and ink on paper.