Bromoil is one of the rarest and most permanent of the photographic printing processes, invented in 1907. The original silver image of the black and white photo is bleached away and then replaced by lithographic ink. The overall process is very tedious and time involved and the end result is one original final print.
Bromoil is an alternative photography technique where the black and white print (made on special paper) is bleached to remove the image. Then, stiff printers ink is used to bring the image back as the ink deposits into the areas where the original print image was.