Tyrian purple by ancient authors. Not much is known about the subsequent steps, and the actual ancient method for mass-producing the two murex dyes has not yet been successfully reconstructed; this special "blackish clotted blood" colour, which was prized above all others, is believed to be achieved by double-dipping the cloth, once in the indigo dye of "H. trunculus" and once in the purple-red dye of "B. brandaris". The Roman mythographer Julius Pollux, writing in the 2nd century AD, asserted ("Onomasticon" I, 45–49) that the purple dye was first discovered by the philosopher Heracles of Tyre, or rather, by his dog, whose
Dye-sublimation printer the print medium. Tiny heating elements on the head change temperature rapidly, laying different amounts of dye depending on the amount of heat applied. Some of the dye diffuses into the printing medium. After the printer finishes printing the medium in one colour, it winds the ribbon on to the next colour panel and partially ejects the medium from the printer to prepare for the next cycle. The entire process is repeated four or five times in total: the first three lay the colours onto the medium to form a complete image; there may or may not then be a