Thank you for your explanation of the dark wrinkles on the shroud. It is difficult to tell from studying internet photos whether the wrinkles are stained with color or merely shadow artifacts as you say. Apparently Wilson has not done his homework then, because he mentions the wrinkles as being colored in support of his theory.
However, he also stated that microscopic studies had not yet been done on his shadow image fibers, though he may consider it in the future. Doubtless there are some people now creating their own backyard shrouds using his method and I expect we will hear more results in the coming weeks.
Shroud researchers have done a commendable job in thoroughly debunking the previous forgery theories such as painting and camera obscura photography, and will doubtless find any fatal flaws in the shadow theory if they exist. But at this point it looks as though Wilson's image has achieved the photo-negative realism and the three-D encoding aspects of the original shroud as revealed by the VP analyzer.
I've looked at Wilson's photos... and I don't really find them equivalent. At first glance, they are very good. However, the subtleties are not there. The shroud's images show a gradations in intensity that is lacking (and may not be possible) in Wilson's photos. The technique of painting on glass, varying the transparency to simulate the distance information encoded on the Shroud, is extremely difficult... and would be even more difficult with the pigments available before 1350.
I again return to the logical argument against this theory. We KNOW what the image is made of... perhaps not how it was made... but what it is. It simply is NOT un-bleached linen. IF Wilson's theory were to be correct, then it would be obvious on microscopic examination. The color of the image and the non-image areas of the shroud would be a quality of the linen... but it isn't.
The image color exists in a very thin (180 to 800 nanometer) coating of dehydrated, oxidated caramel like product; a brown nitrogenous polymers called a melanoidins. This is NOT something that is caused by Paint on glass shadows preventing sun bleaching. This coating can be removed from the linen which then become indistinguishable from non-image linen. That means that the image color IS NOT A QUALITY OF THE LINEN... and ergo, it is not a result of bleaching.
I am attending a Shroud Symposium next Saturday where my friend, Barrie Schwortz, will be speaking. Barrie was the visible light photographer for STURP's 1978 scientific examination of the Shroud and maintains www.shroud.com, the best source of all the research on the Shroud. I intend to query him about the photographic comparisons of Shroud to Wilson Theory pictures. I will post what I learn on FreeRepublic that evening.
You can also check out shroudie's (Dan Porter) web site: ShroudStory.com for information on the latest research.