If it's a hoax it's a darn good one, continuing to stump us for all our 21st c science. I wouldn't make up my mind on the absence of another cloth. If some unknown energy transferred the image onto the shroud, it might also have transferred an image onto a napkin---some lost souvenir we can't examine. And how uniform was the practice of preparing the dead, do you know? I've been reading about the shroud since the 1960's, my verdict is still out. It would be nice to have a photographic record of the Lord but perhaps holiness in an object is still more mischief than it's worth.
I don't think it's a hoax, but at the same time I don't think it's what its supporters claim it to be. For some time now I've toyed with the idea that ionizing radiation might have produced the image. But where would the radiation have come from? If the prototype for the image had been a piece of statuary, it might have come from radioactive elements that occur naturally in many kinds of rocks, especially of the sedimentary variety. Now, the Byzantine story of the Mandylion (which many believe to have been the shroud, folded over and kept within a frame) says that the cloth-bearing image was found in proximity to a "tile" that had an exact copy of the image imprinted on it. Supposedly the cloth had been placed in a niche in the walls of Edessa, and the tile placed in front of it for protection; the image then sat in the niche for several hundred years before its discovery during a siege. Suppose, however, that this story has it backward: suppose that it was the tile that had been placed in the niche, and the cloth placed over it for covering. Over the course of several centuries, radioactive material in the stone might have produced sufficient ionizing radiation to oxidize and discolor the threads of the cloth in proportion to its proximity to the tile, thus producing the image we know as the Shroud of Turin.
The Edessans who discovered the tile would have been hard-pressed to explain what they had found, but to their minds the image on the tile would have appeared less miraculous than that on the cloth. Hence the cloth would have been regarded as divinely wrought.
This is true, but if there was a napkin then there could be nothing resembling blood on the spots on the shroud where there appears to be a trickle of blood on the forehead of the man of the shroud.
And weren't those spots proved to have been dlood years ago?.