ponzo/poggendorff

A variant on Gianni Sarcone’s Op Art illusions, this coffer illusion (referring to the sunken panel elements that most people perceive first) but if one focuses on the x, an array of sixteen circles begin to emerge. Having more than just ornamental value, coffering was a common feature of domes and vaulted ceilings as a load-bearing decoration, each of the lacunaria (openings) making up a strengthening framework.