“That thing gets replicated all the time.”
The image is something like a scorch mark on the surface of the fibers. It’s not paint. No one has figured out how the image was made. I’ve never heard of a single successful effort to duplicate the it.
Since you have, please tell us what museum or art gallery has one of these replications so that we can find out how they did it.
It’s not even a scorch mark. We actually know what the image is composed of. . . it’s made of a microscopically thin coating, less than a couple of ångstroms thick, far thinner than the walls of a soap bubble, on the linen fibers that came from the retting (washing with soap wart) used in preparing the hanks of threads prior to weaving the cloth. Those linen fibers with bits of image on them are no different from the non-image linen fibers near by which also have the same thin coating, except for one critical difference: the coating surfaces of those image bearing fibers, to distance thinner than the wall of that soap bubble, are apparently aged more than those without an image element in some kind of melanin reaction, the same reaction that causes newsprint to turn yellow-brown as it ages.
As the other non-image fibers get older, they too, will slowly take on the hue of the image surface fibers and the Shroud’s image will slowly fade into obscurity as the background color darkens to match.
This aging of the non-image linen fibers accounts for the reports that the Shroud’s image was easier to see in earlier years. The reason was then the background linen was much whiter and the contrast with the image elements would have made them stand out better. The Shroud’s background linen has undergone 700 more years of exposure to air, pollution, and light. Only recently has it been started to be being stored in an inert atmosphere.
We still have no clue how these fibers were altered in a way that was collimated only vertically in both up and down without any horizontal variation by so much as a degree from the vertical, and linearly proportionate in intensity to the distance of the body the cloth covered, thus creating in two dimensions an accurate three-dimensional terrain map of that body of up to a distance of approximately 13 cm distance from the cloth. No known light phenomenon attenuates so rapidly in such a short distance and radiation attenuates at the cube of the square of the distance in a globular fashion, not linearly, nor collimated. Gaseous emission will diffuse into chaotic clouds and are temperature dependent to either rise or fall, not both simultaneously, and certainly not collimated. Electrical phenomenon may account for it, but generally, electron charge flow finds the easiest path to ground, i.e. the highest point and would ignore the lower lying details. Plasma glow discharge may be the only possibility left except, Da Vinci’s time machine. . . That’s a joke, people. . .