Why an Atheist Thinks the Shroud of Turin is the Real Deal

Walter McCrone

One the flip side of the authenticity debate is the claim that one scientist, the late Walter McCrone (1916-2002), found red ochre (hematite) and vermilion (mercuric sulfide), common medieval paint pigments, and thus was able to argue that the shroud was painted. But that claim has since been proven wrong. Scientists—and we should probably only consider those who have actually looked at shroud fibers with microscopes and advanced scientific instruments—are quite certain about the chemistry of the images, and they are not made up of inorganic compounds McCrone identified through the lens of his microscope. The images are the result of a chemical change either to the fibers themselves or to some organic material on the fibers that was there before the images were made.

An analogy is in order. If you have a personal computer, you probably have an inkjet printer attached to it. When you print a picture, tiny droplets of ink are deposited onto the paper through tiny nozzles in a print head that passes over the paper. This is applied color. But it doesn’t really matter how color is applied with a paint brush, a pallet knife, drizzled on as Jackson Pollock did on his canvasses, powdered on as makeup is sometimes applied, or ink-jetted on. And it doesn’t matter if the colorant is paint, lipstick, dye or ink. The operational word is applied.

But there different types of printers that are inkless. Images are formed by a color producing chemical change to the media or to a coating on the media. One common type of inkless printer is a thermal printer. Thermal printers are often found in ATMs, cash registers and older fax machines. Paper that is coated with thermal sensitive chemical passes under a print head that heats tiny regions of the paper resulting in a chemical change that is evident by the change of color. This is not to imply that the images on the shroud were produced by heat. Many things can cause a color producing chemical change including other chemicals. Old newspapers that have become yellow, leaf stains on concrete, rust, these are all examples of color producing chemical changes.