Kasper Feyrer, Rule of thumbs: Double Negative, 2012, antiqued/distressed pine wood frame (beaten with chain, orange pekoe stain), cyanotype on watercolour paper, two dead aa alkaline batteries, magnets, mirror inset, “alte deutsch” architectural glass, thumb fingerprints dusted with bi-chromatic fingerprint powder, 15 x 12 in. (39 x 30 cm)