Guano belongs to a group of works formed of an accretion of paint falling from other works onto a canvas laid on the studio floor. Accumulated and compacted by chance, they developed an extraordinary crust from which they take their name. On reviewing these scarred surfaces, Reigl reworked and scraped back areas. Long striations mark the surface, lending it a sense of order and resolution, and suggesting an archaeological stratification.
The textures evoke urban surfaces, from pavements to ancient walls and, by extension, a sense of an embedded history.