What is right or wrong with this material from page 9 of The Shroud: A Critical Summary of Observations, Data and Hypotheses, by Robert W. Siefker and Daniel S. Spicer.
Table I, Item 5.0:
The front image, at least in correspondence of the face, is doubly superficial. This means that the 0.34-mm thick fabric presents a superficial image on one side (about 0.03 mm thick), no image in the middle, and another superficial image on the other side.
This double superficial image of the face was discovered when the Shroud backing cloth was removed during the 2002 preservation project. This double superficiality is highly significant in relation to the viability of competing image formation hypotheses.
Is this “Established?” Really? It is interesting to note that the Valencia consensus omits this fact. Why?
And because we know where Siefker and Spicer are going in this paper, it is fun to consider the fact that Ray Rogers wrote:
When a cloth is dried on a line, impurities concentrate on both evaporating surfaces; however, more impurities will deposit on whichever surface dries faster. Any concentration of impurities can take part in the image-formation reactions. This can explain the "doubly superficial" image.
BTW: I really do think I see it. I know. I know. I think I see.