Colin Berry wonders: Why is the Shroud image so superficial, half-tone and striated? Is it on raised ribs of primary cell wall hemicellulose? With an interesting graphic, he helps us to imagine a possibility:
Note the way that the hemicellulose forms a series of interrupted striations on the surface of the cellulose fibrils. Then imagine an image being thermochemically imprinted by some means onto that surface. It is not difficult to see how the resulting image might exhibit bothhalf-tone character AND striations as reported per Shroud image if there were selective pyrolysis (chemical dehydration to yellow or tan products) of those interrupted hemicellulose bands or segments, leaving the cellulose relatively intact.
It may be time to restart those kitchen experiments. It could start with attempts to strip off the outermost PCW layer of cells selectively, or even the hemicelluloses only, and see whether the surface then resists thermochemical dehydration (aka “scorching” .
Bravo to new ideas and experimentation.