imageNice, neat summary from jonam mk in Madurai,Tamil nadu,India:

The Shroud’s images are superficial and fully contained within a thin layer of starch fractions and saccharides that coats the outermost fibers of the Shroud. The coloration is a caramel-like product or the product of an amino/carbonyl reaction. Where there is no image, the carbohydrate coating is clear. There is also a very faint image of the face on the reverse side of the Shroud which lines up with the image on the front of the cloth. There is no image content between the two superficial image layers indicating that nothing soaked through to form the image on the other side.

Pretty much what I think. Actually those are my exact words. That is the world of blogging. And it is fine with me. A link would have been nice, something  like