The Shroud's image happened because a hot, sweat, blood and serum drenched body was in contact with the cloth for about thirty- six hours. We can duplicate the effect. Just recently they did it in a duplicate ambience in Jerusalem. Jerusalem, Asia Minor, Byzantium, France and Italy. Even the limestone on it is uniquely from Jerusalem.
Identifiable traces suggest that Jerusalem dirt fell off the victim's feet.
The serum is human. We have many samples of funerary linen preserved from antiquity. None showed any image of the body they contained. Yet an image, a mercerization of the linen, appears on the Turin cloth. This might be either from a living body or from an equivalent model.