fibers, when bloody - bloody well bloody - can stretch. john 19:34 'but one of the soldiers pierced his side with a spear, and immediately there came out blood and water.' Jesus was ALREADY dead - so this was one of the last things they did to him (they were going to break his legs and hasten death - but he was already dead). so, right after these things - joseph of arimathea, being a disciples of Jesus (but a secret one), for fear of the jews, asked pilate that he might take away the body of Jesus; and pilate granted permission...so they took the body of Jesus and bound it in linene wrappings with spices, as is the burial custom of the jews.'
now, the shroud is known to have the burial techniques of the first century and not of middle ages. also, noone can figure out how the images are imprinted onto the linen. we don't even know the techniques themselves! there is NOTHING to compare this technique WITH.
john 20:5 and 'stooping and looking in, he saw the linen wrappings lying there; but he did not go in. simon peter therefore also came, following him, and entered the tomb; and he beheld the linen wrappings lying there.'
now, in my estimation (and i could be wrong - but the dating is interesting to be 1st century) - the 'face-cloth' was sewn to the rest of the shroud.
'and the face-cloth, which had been on His head, not lying with the linen wrappings, but rolled up in a place by itself.
now, the linen wrappings COULd have completely wrapped his body head to toe - and the 'head wrapping' been an additional wrapping that was unable to be completed over the entire body because of the jews 'preparation day' and laid in the garden in a new tomb (john 19:41), in which no one had yet been laid. this would indicate, to me, that the fibers would be holding mostly only Jesus blood and flesh - and yet - when the x-ray or ressurrection happened - his body and flesh were suddenly changed. this is the part where the 'reverse' image happened. who can 'make' a reverse image like this from being dead to alive? we don't know HOW GOD DID THIS. it is not a typical type of thing. otherwise we would find others just like it.
it would be interesting to find out the history of who had the shroud - when.