About the first point, that's true, but mostly irrelevant. There are many niche painting techniques lost to time. Even more so, no one can truly predict the eff

About the first point, that's true, but mostly irrelevant. There are many niche painting techniques lost to time. Even more so, no one can truly predict the effects 6 centuries of display and exposure and a fire will have on some obscure painting style. We know there are traces of pigments on the cloth, so probably at some point there was much more. It was almost certainly a much less convincing and haunting image at the time it was made, the centuries of wear have just hidden the more obvious marks. The second point was only in reply to someone saying "but what if it was some random shroud from the 1st century unrelated to Jesus?", and I merely explained why that makes much less sense than even the miracle explanation.