The Shroud has been dated to at least the first century, and pollen indicates a location near Jerusalem. The image, which is in 3d and no traces of ink, strongly indicates something supernatural caused it. The image contains blood stains in a pattern exactly as would be expected of someone who had been, first severely whipped, and then crucified.
If it isn't the image of Jesus, then who? Some other person who was crucified and then bodily resurrected? Now THAT really would blow the top off of Christianity!