Image Fibers Are Fibers Containing Image Information
When scientists refer of image fibers they are referring to a coating on lengths of fiber that have undergone a chemical change that produces image color.
Cellulose fibers that compose the threads of the Shroud's cloth are coated with a very thin layer of starch fractions, various sugars and other impurities. This chemical layer is thinner (200 to 800 nanometers) than most bacteria. It is thinner than the walls of a soap bubble. It is less than 1/100th the thickness of typical human hair.
This coating is essentially colorless. However, in some places, the coating has undergone a chemical change that appears straw-yellow. This chemical change is similar to the change that takes place when sugar is heated to make caramel or when proteins react with sugar as in the making of beer. And it is the straw-yellow color, selectively found in some parts of the carbohydrate layer, that makes up the image we see on the Shroud.
