A photochrom print depicting “The Blue Grotto” in Capri Island , Italy, one of several sea caves, worldwide, that is flooded with a brilliant blue or emerald light. Photochrom prints are made by colorising images produced from black-and-white photographic negatives via the direct photographic transfer of a negative onto lithographic printing plates. In this particular image, the process has been carried out to such a degree as to give the couple in the boat a distinct, and almost ghostly, painterly effect.