These red images are produced on a reactive film that changes color with pH. Alkalis and acids are applied to achieve an image: acids create yellows and alkalis create greys and blues. The inspiration for this was the series of copper plate images, which had been drawn upon with rust and water.
The yellow images were produced on hard paper with traditional lead pointer and triangle and then transferred to clear acetate with copier toner and bound into multiple layers to create the a translucent series which was finally re-inscribed on the rubylith with razor points to complete the series.