It's not propaganda, as it refutes some of the commonly-recited chestnuts in favor of the Shroud. It is trying to look at the totality of the evidence and not cherry pick from either side.
Apparently you are making a compound error--
1) conflating 'skepticism' with 'materialism'
2) assuming that since 'of course' the Shroud is evidence of the Supernatural, then by definition it *must* be fake.
Maillard reactions are well known completely outside of the Shroud, as in cooking and in aging
The point being that outgassing of various organic compounds from a newly-dead body would react with the starches in the linen shroud, to colorize the fabric. Such a process would be consistent with certain aspects of the appearance of the shroud not accounted for otherwise; and would provide a more consistent mechanism then positing an unknown medieval artist who took care to fake things invisible to the naked eye, unknown to the science of his time, and inconsistent with the contemporary beliefs about crucifixion (not unique to Jesus, you know) and yet shown to be accurate later.
And all this without requiring you to give up your emotionally clung-to disbelief.
Cheers!
It asserts things that aren’t true, is my problem with it, and is written up by some bum who surfs Wikipedia for his info. If you love it, fine, but don’t offer it as something it is not.
Quite true- the thumbs are drawn in because the nails pierced the wrists. All contemporary art shows the nails in the hand- A great (and telling) technological difference, to be sure.