Bittman's work is acrylic on handwoven textile. You can even sense a bit of the movement, the pulsation, in these pieces in the photos. They are intricate and seem to change before your eyes. Both pieces are untitled.
Opera's Sun Sky 06 is Cyanotype on stretched linen canvas in an artists frame. A cyanotype is a photo printing process--the same used to create "blueprints."