I used to live in an old house. All the windows, and there were many of them, were made up of twelve individual panes of glass, each one held in its place by a thin wooden grill with window putty. One year, in the Spring, after we took down the winter storm windows and put them away in the garage, my father told me I was old enough to climb a ladder and perform the annual painting of the grills and the putty. And I was not, of course, to get any paint on the glass.
“Use masking tape,” my father advised. “It will make it easier to avoid getting unsightly paint on the glass.” But being fourteen, I knew better. I would use a thin sable hair artist’s brush and paint very accurately. Well, a week later, I found myself up on the ladder again, now scraping paint away. Big globs, sometimes as thick as a penny covered parts of many glass panes.
. . . chemically-modified cellulose – as declared by STURP’s 1981 Summary – formed with no extraneous add-ons- OR whether it shows a better match with Maillard browning product . . .
Did you know they make razor blades specifically for scraping paint from glass, chewing gum from the soles of shoes, and splatted bugs from automobile windshields. I once watched a sidewalk artist in New York use a razor blade to scrape all the paint off a finished portrait of a tourist who had stiffed him so he could use the canvas again to paint another tourist.
So I was puzzled when I read the sentence below (emphasis mine, in red) about the Shroud’s image at the Sign From God website.

Fact: The image of the man does not penetrate the cloth as it would if any artistic substance was used by someone to create the man’s image. In fact, the best chemistry regarding the image is that it is simply a discoloration of the cloth as a result of something having caused the accelerated dehydration and oxidation of the cellulose linen fibers but only in those areas immediately surrounding a body. The image affects only the cloth’s top two microfibers. It is so thin it can be scraped off with a razor blade. Furthermore, the image is uniform in intensity throughout the entire cloth with no variation in density or color—an impossible feat for any artist of the Middle Ages.
So what does it mean it was so thin? Almost any thickness of almost anything can be scraped off with a razor blade. I left in the full paragraph above hoping for some context. I think I know what SFG is trying to say. Maybe, try reading the first sentence and the red-letter sentence together.
I tried to figure out where the razor blade idea came from. It turns out that red-lettered sentence is very similar to a sentence in an article, The Shroud of Turin, Authenticated Again, in National Review back in April of 2016 (limited free access).
Here is a startling fact that makes the Shroud nearly impossible to be considered a forgery and enhances the mystery. Unlike his blood, the man’s crucified image does not penetrate the cloth but rests on top. His image could be scraped away with a razor blade. Since any earthly substance used to create the man’s image would seep into and adhere to the cloth, this lack of penetration continues to baffle modern science.
In seeing National Review it makes more sense. But is the SFG statement factually correct? Is this really the best chemistry? Is the chromophore simply discoloration? Is accelerated dehydration and oxidation of the fibers the best way or even the right way to describe it? Is it true the image affects only the cloth’s top two microfibers?
That overall narrative about the image has been challenged. What follows, is something I wrote in an essay, Slouching Towards Emmaus And Some Nonsense Along the Way.
[What we know] doesn’t mean that the cloth was not draped over the body of a crucified man at some time. That is highly possible. It was possible enough for John Dominic Crossan, a very controversial Jesus Seminar Biblical scholar, most noted for his assertion that Jesus was not buried, to proclaim on Belief Net.
My best understanding is that the Shroud of Turin is a medieval relic forgery. I wonder whether it was done from a crucified dead body or from a crucified living body. That is the rather horrible question once you accept it as a forgery.
Dr. Michael Tite, who in 1988 led the British Museum’s oversight role in the carbon dating process and later was Emeritus Professor of Archaeology at the University of Oxford, implied something similar in a BBC Radio interview in 2016:
I don’t believe it’s the [authentic] Shroud but I think it is highly probable there was a body in there. It was the time of the Crusades. A very appropriate way of humiliating a Christian would be to crucify him, like Christ. I think that is a very real possibility. And then the cloth is put over the body and sort of bodily fluids resulting from the stress of a crucifixion react and cause this discolouration and ultimately a certain degree of decay in the Shroud.
Really? Bodily fluids reacting? We have been down this road before, back in the 1930s and again in the 1970s, before STURP.
Nonetheless, I’m thinking as I write this. There is, even among some skeptics, a recognition that we don’t have all the answers.
It’s not that it isn’t easy to make something that looks like the Shroud on a piece of linen. It is relatively easy. But there are other image characteristics that must be met. We thought we had a good handle on these when STURP issued its Final Report in 1981, as well as an official summary distributed to the press. Having learned new things since then, some assertions need to be reexamined and maybe changed.
For instance, we may have gotten the physical and chemical nature of the image chromophore all wrong. The summary reads:
The scientific concensus (sic) is that the image was produced by something which resulted in oxidation, dehydration and conjugation of the polysaccharide structure of the microfibrils of the linen itself.
That statement in slightly different grammatical constructs may be the most stated assertion about the Shroud’s image, ever. It may be repeated even more than the line about paintings and photographs not producing 3D. The most significant change you ever see is to correct the spelling of consensus.
Consensus is an important word here. It strongly suggests something other than unanimity. And indeed, STURP chemist Ray Rogers had other ideas. With Dr. Anna Arnoldi from the University of Milan, he published a significant paper in 2002. They proposed something else. Ray Rogers and Dr. Arnoldi are clearly not part of the consensus. They wrote:
I [= Rogers] believe that impurities in ancient linen could have been suspended by the surfactant property of a Saponaria officinalis washing solution. They would be concentrated at the drying surface by evaporation. Reducing saccharides would react rapidly with the amine decomposition products of a dead body. This process could explain the observations on the chemistry and appearance of the image on the Shroud of Turin. Such a natural image-production process would not require any miraculous events; however, it would support the hypothesis that the Shroud of Turin had been a real shroud.
The observations do not prove how the image was formed or the “authenticity” of the Shroud. There could be a nearly infinite number of alternate hypotheses, and the search for new hypotheses should continue.
If shroudies gave a prize for objectivity, it should go to Ray Rogers – regrettably posthumously – for that short second paragraph. I suspect there are, indeed, many hypotheses. And we haven’t even thought of many of them.
And if they gave a prize for admirable chutzpah, it should go to the Shroud’s most qualified skeptical chemist, Dr. Berry. He has identified a technology that:
appears to provide a potential means for exploring the chemical make-up of the image chromophore (something that has evaded science for the best part of 40 years – and more!).
More to the point, it provides a means (hopefully) for distinguishing between rival models – notably the ones supplied by STURP (2 contrasting models – modified cellulose v Maillard!) and now my own Final Model 10 (“FILM-SET”).
No, we don’t need – as yet – to go the whole hog, i.e. to determine the detailed chemical structure of the image chromophore. No, far from it. Let’s be content (for starters) with determining whether or not the fragmentation pattern seen on mass spectrometry is that from a chemically-modified cellulose – as declared by STURP’s 1981 Summary – formed with no extraneous add-ons- OR whether it shows a better match with Maillard browning products, involving amino-carbonyl reactions in the first instance (the nitrogeneous amino groups supplied by additional non-cellulosic participants!).
The short, so often cited page called, STURP’s 1981 Summary is a problem. It’s a problem for skeptics and authenticists alike. More work needs to be done before we can call the chemical nature of the chromophore a fact.
A typical single edge, uncoated carbon steel, laboratory grade razor blade is about .228mm thick with a 20 degree cutting edge. That’s about 2/3 of the thickness of the Shroud. We probably need something much thinner and sharper.
Well, that’s an interesting and wide ranging collection of comments!
1) The razor blade thing was surely an ill-advised metaphor. Take any razor to the Shroud and you’d rip it to shreds. The idea, I suppose, is that a razor is a little more discriminate than a paint-scraper or a snow-plough, and that the image of the Shroud does not penetrate the cloth, as can easily be seen on photos, does not penetrate the threads of the cloth (much, although two or three fibres deep is sometimes mentioned), and does not penetrate the individual fibres (more than the depth of the primary cell wall). All probably true, but all often assumed to be evidence that the image must be miraculous and not paint, which is absurd. Applied chromophores, whether they be dry powder, wet paint, or starch, would neither penetrate nor react with the fibres at all, just sit on top in a very thin layer. Whether it penetrated the threads, or the cloth, would be a function of the tightness of the spinning and the tightness of the weave, and the Shroud seems very tight in both respects. Degrading the surface layer of the fibre – that dehydrated/oxidised celulose guess by Heller and Adler – could be achieved by radiation or by chemical reaction with, say, acid, which could be a property of the paint medium, or a salt, such as iron acetate, which could be part of a dye.
2) The official summary of the STuRP investigation was published in the peer-reviewed Analytica Chimica Acta in 1982. It was called “Physics and Chemistry of the Shroud of Turin,’ bylined ‘A Summary of the 1978 Investigation,’ and authored by Larry Schwalbe and Ray Rogers. It should not be confused with “A Summary of STURP’s Conclusions,” which was never published in any journal, was “distributed at the press conference held after their final meeting,” is undated and significantly, unauthored. The first is measured, takes a great many studies into account, and is cautious in its conclusions. It does not claim any consensus. The second is declamatory, over confident, and claims, without any justification at all, to represent a consensus, which it doesn’t. It doesn’t even represent a consensus among the STuRP scientists, let alone scientists in general, who mostly did not then, and do not now, agree with it. What it does represent is the beginning of a widening rift between two factions within the STuRP organisation, which has not been fully documented, but hints of which can be found among the works of John Heller and Eugenia Nitowski, to name but two, and the original preface to Ken Stevenson’s book, Verdict on the Shroud.
3) “There is, even among some skeptics, a recognition that we don’t have all the answers.” There is indeed. This is less true of authenticists, however, whose works are peppered with phrases such as “the only possible ….” The two best exponents of authenticist confidence are John Jackson, whose Critical Summary of all the evidence shows that only the ‘Fall Through hypothesis” accounts for all his 17 criteria, and Giulio Fanti, whose Critical Compendium finds that only the ‘Coronal Discharge hypothesis’ accounts for his 24 criteria.
Hi, Danm,
I have been following your comments on the Shroud of Turin for quite a while. I may have missed it, but has it ever been compared to other shrouds of crucified victims?
As far as I know, there is no archaeological finding of a shroud belonging to crucified victim. There are very few burial cloths from the 1st century Palestine, the only known specimen are Akeldama burial shroud, and perhaps a few fragments from Qumran cementery. Simply, burial linens are too fragile and deteriorate easily.
There is no known image on the burial cloth that is comparable to the Shroud of Turin.
“Simply, burial linens are too fragile and deteriorate easily.”
Is the above sentence beneficial to proponents of authenticity ?
OK knows better than I do. But from what little I know, I agree with OK.
You make an important point. But the allure of “only one” exclusivity is provisional. We must thrust upon it “as far as we know” caution.
Thanks, and I apologize for my slow response.
Paolo Di Lazzaro of the Shroud Science Group asked me to send along his comments to Dan:
The sentence “The image is so thin it can be scraped off with a razor blade” is unscientific, not quantitative, and in my opinion can be easily dismissed as nonsense.
It is one of the many pieces of nonsense that we can read in blogs, newspapers, magazines and books about the Shroud, without the respective authors ever having studied a single scientific article authored by STuRP scientists.
The questions I ask myself and ask you is the following: why does a Shroud scholar question whether an obvious nonsense written in a magazine/blog/newspaper is really nonsense?
To be sure that it is nonsense one would just have to read and refer to scientific articles written by scientists who have studied the Shroud in person, in depth.
Incidentally, all STuRP articles are freely available on Barrie’s wonderful site, and the majority of articles subsequently published in serious peer-reviewed scientific journals are freely available at several sites, e.g., Academia.edu and Researchgate.net
I know one possible answer to my question: those without a scientific background cannot understand a specialized scientific text, let alone check whether a statement makes sense or not.
As a result, scholars without a scientific background refer to texts without any check or verification of veracity. At best, these are texts that report what the author has understood about a true scientific paper (sometimes they do not quite understand), but more often they are copy/paste of other texts with personal additions, sort of an initial core of inaccuracies that spreads and grows larger, like an avalanche, from copier to copier.
But this possible answer generates another question: why does a person who has no scientific training feel like discussing scientific topics in which he or she is not knowledgeable? This is the question of questions, given the flourishing of nonsense written by scientific illiterates scattered in abundance across the web.
As I had occasion to remark in a review of scientific statements (sic) written by historian Nicolotti in his latest book, “To mitigate the consequences of this know-it-all attitude, one must be aware that Science is not democratic, in the sense that not all scientific opinions hold the same value. To express sensible opinions, it is required professional skill and years of study and practice. To each their own job, indeed.”
To conclude, here are my answers to Dan’s questions, based on scientific literature and experiments done directly on the Shroud.
Is the chromophore simply discoloration?
Yes, at the moment the available data show the most plausible explanation of the Shroud image color is the generation of a chromophore (double bonds C=C and C=O) on linen cellulose. See the papers by Heller Adler “A chemical investigation of the Shroud of Turin”, Canadian Society of Forensic Science Journal vol. 14, pp. 81-103 (1981)
and also
L.A. Schwalbe, R.N. Rogers: “Physics and chemistry of the Shroud of Turin, a summary of the 1978 investigation” Analytica Chimica Acta 135, 3-49 (1982).
and
E.J. Jumper, A.D. Adler, J.P. Jackson, S.F. Pellicori, J.H. Heller, and J.R. Druzik, “A comprehensive examination of the various stains and images on the Shroud of Turin”, Archaeological Chemistry III: ACS Advances in Chemistry 205 (American Chemical Society, Washington, 1984), pp. 447-476.
Is accelerated dehydration and oxidation of the fibers the best way or even the right way to describe it?
Yes, it is the best way to describe it the yellowing of the cellulose molecules. That this is the “right” and definitive explanation can never be said in science. We can say that it is the best explanation based on the available experimental data, see the paper by Heller Adler quoted above.
Is it true the image affects only the cloth’s top two microfibers?
Based on STuRP and subsequent samplings, the answer is yes. But to be more sure, one would need to have a statistic of many additional fibers distributed over the entire image.
Finally, I cannot agree with the final sentence of Dan’s post: “The short, so often cited page called, STURP’s 1981 Summary is a problem. It’s a problem for skeptics and authenticists alike. More work needs to be done before we can call the chemical nature of the chromophore a fact.”
In fact, the STuRP summary was the “translation” made to be understood by journalists of an extreme summary of dozens of articles already published in scientific journals. Obviously, in the summary some important things are lost, but the fault lies not with the STuRP scientists, rather with the journalists who do not know the basics of chemistry, physics, biology but quietly talk about them as if they were experts. If one wishes to “call the chemical nature of the chromophore a fact” he/she has to study basics of chemistry and physics of materials, and then read the above quoted papers. Most questions find an answer (or partial answer) in the STuRP papers.
I am reminded of an aphorism attributed to Einstein in 1933: Everything should be made as simple as possible, but not simpler.