A statistical model of the relative print order of Renaissance prints:
Hedges, a biologist whose hobby involves Renaissance prints and maps, developed his “print clock” method by first measuring time-related changes in 2,674 Renaissance works. He found that the number of breaks in the lines of images printed from woodblock carvings increased over time, while the image intensity became more pale in copperplate prints. “Because woodblocks and copperplates were expensive to replace, they commonly were reused for decades to produce multiple editions of a book or print,” Hedges said. His methods include taking digital photographs of the prints, which he analyzes with standard statistical methods and with widely used image-analysis software. Working with black-and-white pixels, the software can detect and count breaks in the lines of woodblock prints and can measure fading of the etched and engraved lines of copperplate prints.
(Via George Hotelling.)