No, it's not photography, but resembles it (pre-digital, using silver salts) by capturing a faint image first, albeit by actual physical contact instead of light, then developing the image using a chemical that makes it more visible. Think of it if you like as 'chemography', rather than photography. Being a contact imprint, rather than a processed photograph, explains why the Shroud image is a negative rather than a positive. Being imprinted off a 3D subject explains why it shows 3D properties when the 2D image is uploaded to 3D-rendering software.
The purpose of this posting is to home in on three of the key variables of the new model to see which of 3 options produce a superior or inferior result. They are: 1. use of cold v hot water dispersions of plain white flour as imprinting medium (cloudy suspension v semi-transparent paste); 2. pressing linen downwards against body part, or pressing body part downwards into linen; 3. using whole flour, with gluten protein, or using starch only, easily extracted from the same flour, free of gluten protein(previous findings with extracted gluten suggesting that it, and it alone was responsible for most of the colour development that is seen when nitric acid reacts with a white flour imprint).
Method: Flour or starch imprints on linen were first dried on a hot radiator, then transferred to a bath of conc. nitric acid solution (approx.70% w/v.) Development is rapid at this high concentration, probably a few minutes, but 30 mins was chosen as standard to ensure maximal colour development. The linens were then washed thoroughly. first in sodium bicarbonate solution to neutralize acid, then tap water, and finally dried over a radiator.
|Left: hot water flour paste v right cold water flour suspension as imprinting medium. with coated hand pressed down into linen. Developed with nitric acid.|
|Hand coated with near-transparent flour/hot water paste.|
|Hand coated with more visible flour/cold water dispersion.|
|Here's a comparison of the two imprinting modes - hand pressed down into linen (left) v linen pressed down onto hand (right) using cold water/flour in both cases.|
|As above, but comparing the fainter imprints from use of hot water pastes (hand down onto linen, left v linen down onto hand, right).|
The next step is to test the ability of the image to withstand various treatments (washing with detergent, boiling etc). However, that must wait a few days: iodine/potassium iodide solution has been ordered to check how much starch remains detectable after second stage development. It might be quite small, given that the rinsing procedures with bicarbonate and water are visibly removing a lot of starch granules (judging by cloudiness in the rinse solutions). Mercifully, the yellow/orange reaction products does not wash off (being insoluble in water - a characteristic of rubbery gluten in any case, even before modification with nitric acid).
Overall conclusion: the methodology is robust and versatile. If one wants a sharp, well delineated image, then use a dispersion of white flour in cold water (less flour/more water than used in this experiment). If one wants a fainter image, then use a hot water dispersion instead, one in which the starch granules are gelatinized (though it's the gluten storage protein that is the "active ingredient" where the second stage colour development with nitric acid is concerned). hat has been conclusively demonstrated here by showing that there is no image if one imprints with wheat starch, washed out of dough, free of the insoluble rubbery gluten protein.
|Dried sediment of wheat starch granules at base of container, washed out of dough by kneading under water (the gluten stays in palm as rubbery mass).|
Here by the way is a result from a previous posting, showing how extracted gluten gives a dark orange colour with nitric acid:
What's the final physical state of that nitrated wheat gluten, once unreacted starch granules have been washed out? Might it be a thin film of protein? Might that account for the superficiality of TS image? Might it account for Rogers' observation that the image layer was left behind in the adhesive coating of his Mylar sticky tape when individual fibres were pulled out using forceps?
Fluorescence of body image under uv (more correctly, absence thereof where the TS image is concerned)? Don't know. I do not own or have access to a uv lamp, and have no immediate plans to buy one, simply to do a one-off test. I'll happily post imprints of my hand to anyone with a uv lamp who wants to check them out. Hugh Farey?
Optimal geometry for imprinting? Press flour-coated body or body part into the linen OR drape the linen over the coated body or body part and press around the contours? Answer: in this experiment, either procedure gave a satisfactory result, with little to choose between the two. There are some other pros and cons to be considered, both theoretical and practical, but the details are probably best left to another day.
Postscript to the "blood too red" mantra
"Where's the photographic evidence?" is the question I posed in the posting preceding this one, and still no one's provided an answer. We've been told that Adler and Heller looked at stained linen fibres from the TS under the microscope, and judged them to be redder than expected. OK, but where's the photographic evidence? We've been told that folk who have seen the TS with their own eyes, maybe with the benefit of some natural light (with a uv component), maybe not, judge the bloodstains to be redder than expected. But where's the photographic evidence?
What is especially irksome to this one-time bilirubin specialist (University of Pennsylvania Hospital Medical School, 1970-72) is the way Adler and Heller's begging-the-question "trauma bilirubin" claim, or as I prefer to call it, fantasy, has become inseparable from the "blood too red" mantra. For a start, bilirubin is not red. It's orange. Ah, but bilirubin is also fluorescent, we're told. so that might explain the brightness of the bloodstains. In fact, bilirubin has scarcely any fluorescence at all under uv. The fact that there's enough to permit a clinical fluorescence assay is neither here nor there. The sensitivity of the eye to mixtures of colours, viewed in diffent kinds of light, natural and/or artificial, and the sensitivity of electronic instrumentation to specific filtered wavelengths in the visible and uv are two entirely different things.
What amazes me is the obsession with bilirubin, almost certainly a total irrelevance, given its instability to light and oxygen (it self-sensitizes its own destruction via a singlet oxygen mechanism), yet next to none of the textbook property of free porphyrins, stripped of iron and protein, such as might exists in ancient blood. Free porphyrins are noted for their bright pink or red fluorescence under uv light (which would include sunlight). The most likely explanation for TS blood appearing too red is that it is being viewed in light that has a uv component, probably daylight. Yet I don't recall ever having seen that alluded to anywhere in Adler's writings, despite him being a porphyrin specialist.
Here are a couple of pictures of porphyrin fluorescence culled from internet image files.
The one above is in a silica cuvette, showing typical porphyrin pink/red fluorescence.
The second (above) is from a skin carcinoma before (right) and after (left) treatment with an agent that stimulates porphyrin fluorescence under uv light.
Update: Thursday 28 May
Here's a diagram discovered on internet image files that shows, in highly schematic form, the relationship between starch granules and aggregates of seed storage protein ("gluten") in the endosperm of wheat grains.
|Protein aggregates are shown as purple zigzag lines.|
Wheat gluten (shown purple) is unique in its hydrophobicity ("water-repellent"), which explains its tendency to self-associate in a dough to make a highly elastic substance capable of trapping CO2 and air bubbles - crucial for breadmaking.
Looking at the diagram, here's a prediction that will be put to the test later today. It should be possible to imprint an image of my hand onto linen, and then, with or without drying, to steep the linen in plain water so as to selectively wash out the starch granules (as in dough-kneading under water that washed out starch to leave an extended gluten network on the linen). Then and only then, one could develop the image with nitric acid. It seems conceivable that the initial washing out of the starch prior to nitric acid treatment might allow the gluten to self-organize into a better 'film' on the surface of the linen, akin to the image-receptive silver bromide emulsions used in photography (except this one would be a chemographic 'emulsion'). The end-result might be superior.
Update: 28 May, 18:35
Well, here's the result of that latest experiment, and I have to say I'm very pleased, very pleased indeed:
|Imprinted linen washed with copious amounts of water before development with nitric acid. Wet imprint washed immediately (left); imprint dried and then washed (right)|
I consider the above result important, in a number of ways. First, one can imprint with a cold-water dispersion of flour, and then wash with water, lots of it, and still get an image instantly recognizable as a hand (mine!). That's not only true if one lets the flour imprint dry first before flushing with water. It's true if one takes the wet imprint and immediately drops it into water, and then rinses repeatedly with additions of water until the washings are clear of suspended starch granules. One might have expected the flour imprint to float off. But it doesn't. Correction. Some of it detaches - the starch granules - as can be seen by holding each discarded rinse up to the light. One sees cloudiness, due to starch granules. One can confirm it's starch that is being washed out by adding Lugol's solution (iodine/potassium iodide). Blue-black stained starch granules gradually settle out on standing. BUT THE GLUTEN PROTEIN OF THE FLOUR IMPRINT DOES NOT WASH OUT. It stays put - all of it. That's because of the unique nature of wheat gluten protein, being highly apolar and hydrophobic, and thus totally insoluble in water (clumping as a water-repellent mass). What one sees above is the gluten component of plain white wheat flour that has NOT been washed out, and which has then produced that orange colour with nitric acid, due to reaction between the acid and the aromatic amino acids of wheat gluten protein (tyrosine and tryptophan especially).
The resilience of the flour image, specifically the protein part, able to cling on when the major starch component washes off, is further testimony to the robustness of the new imaging technique.
Word of advice: if anyone's thinking of repeating these experiments, it's important to use one's dispersion of flour paste the same day. Don't be tempted to store in the refrigerator. Why not? Because the gluten separates out as clumps. They darken quickly (why?). One doesn't want one's gluten in clumps - it needs to be dispersed in order to imprint a contact image.
Update:Friday 29th May
How firmly are those images attached to linen in the above photographs of my hand? I've been trying to detach them, first by wrapping the linen in a cotton bag, and then kneading the bag vigorously for a minute or two, then opening to view the result. amaxing. Scarcely a single particle of image detached. It's as if it were glued on (which in a manner of speaking it is). I even tried kneading small parts of the image directly over spread-out cotton to catch any particles. There were none, none whatsoever.
Mechanical action, then, does NOT detach the image. Some alternative treatments will be investigated, e.g. boiling water. (No sense in testing cold water, since the image has already survived that in the process of washing out the nitric acid).
I shall also be making some observations here regarding STURP - whose efforts have been lauded on the shroudstory site (my italics).
The more I look at that 1981 Summary, the less I like. STURP went in as chemical analysts, photographers, technologists etc etc, but STURP did not go in as I believe fundamental scientists would or should, starting with well-informed hypotheses ("educated guesses") for testing based on the existing facts. STURP went in as if there were no existing facts, certainly not Secondo Pia's stupendous discovery of the negative image (one that incredibly gets no mention whatsoever in the Summary). More later (but there are more tests to be done first on the new imprints - IMPRINTS note, that's NEGATIVE imprints).
Update Friday 11:00
Here are 12 photos, hot from the press, showing what happened (or didn't happen) when I tested the flour/nitric acid imprint of my hand for physical resilience, hoping to learn something about its likely permanence, vis-a-vis the TS image.
1. Here's the starting image, before subjecting to 4 tests, all performed cumulatively on this same sample.
2. Here's the sample folded up, ready for wrapping in a cotton sheet, that will then be crumpled repeatedly to see if the image can be dislodged ("flake test").
3. All ready for pummeling manually.
4. Scarcely any image flaking or detachment, except for one ot two minute particles.
5. The linen was then placed in a saucepan with water and brought to the boil, then simmered for a few minutes.
6. The image survived this brutal treatment unscathed. Virtually no colour entered the water (see measuring jug).
7. Here's the image after those first two treatments, still recognizable as my hand. Compare with 1. above.
Reminder from shroud.com (History of Shroud - my red highlighting):
April 14, 1503 Good Friday: Exposition of the Shroud at Bourg-en-Bresse for Archduke Philip the Handsome, grand-master of Flanders, on his return from a journey to Spain. The Shroud, which has been specially brought from Chambéry, with great ceremony, by Duke Philibert of Savoy and Duchess Marguerite, is exposed on an altar in one of the great halls of the Duke's palace. Savoy courtier Antoine de Lalaing records of the events of that day: "The day of the great and holy Friday, the Passion was preached in Monsignor's chapel by his confessor, the duke and duchess attending. Then they went with great devotion to the market halls of the town, where a great number of people heard the Passion preached by a Cordeilier. After that three bishops showed to the public the Holy Shroud of Our Lord Jesus Christ, and after the service it was shown in Monsignor's chapel." Lalaing adds that the Shroud's authenticity has been confirmed by its having been tried by fire, boiled in oil, laundered many times 'but it was not possible to efface or remove the imprint and image.'
8. The third test was rub vigorously with a toothbrush. There was NO image detachment whatsoever.
9. The sample was then wetted and given a coating of soap. It was then kneaded vigorously.
10. Finally a result. most of the image disappeared. but the rinse solution did not have the expected yellow or orange colour. What had happened to the image pigment, presumed to be nitrated wheat gluten?
11. Here's the final laundered linen, after ironing. there's the faintest hint of a 'ghost' image if one looks closely. It was entered into my photoediting program to see if it was really there, and not a figment of one's imagination.
Interpretation: well, there were some surprisesthere. Who would have thought that an image formed by imprinting gluten protein onto linen would be so resistant to removal, at least by (a) mechanical action and (b) boiling water. Scarcely any was removed by either of those treatments. But the biggest surprise was the effect of plain soap: it removed almost all the image colour, but the rinse water was not coloured up proportionally, judged purely by eye, admittedly. Where did the colour go? Up until now, I have been assuming that since it's the gluten fraction (not starch) that gives the orange or yellow colour with nitric acid, one is seeing the well known xanthoproteic reaction that occurs between nitric acid and aromatic amino acids - tyrosine and tryptophan expecially, due to nitration of aromatic rings. It's the chemistry that accounts for the orange colour of nitric acid stains on skin (this researcher has acquired one of those recently through failure to wear gloves 100% of the time).
So where does that leave us? Seems one will have to keep an open mind as to the nature of the orange products formed with gluten and nitric acid. It does not make sense that soap should bleach that colour. Might the colour somehow be masked by micelle formation between soap and protein? Maybe, maybe not. But there's another possibility, namely that the orange chromophore is NOT nitrated protein (despite expecting it to be there). Might the nitric acid have found something else in wheat gluten, or a trace component of wheat flour, that is something other than a nitrated protein? The plot thickens.
I shall try repeating the experiment substituting a synthetic detergent for soap, and see if it too bleaches or otherwise sequesters the orange colour of the hand imprint.
Update: Yes. the apparent disappearance of the image chromphore seems to be an artefact of using soap. Replacing soap with a synthetic detergent gives a different picture entirely:
Here's the detergent, which was chosen because it's (a) colorless and (b) being synthetic does not form a precipitate ("scum") with calcium and magnesium ions in hard water and (c) just happened to be under the kitchen sink with all the other cleaning aids.
Here's the relatively clear and colorless rinse water after washing the imprint with undiluted detergent. This time the removed pigment is visible, having settled out at the bottom of the container. Forget what I said earlier about the chromophore being something other than nitrated protein. What we see above is entirely consistent with nitrated gluten, the latter retaining its insoluble properties.The detergent or indeed soap functioned presumably to loosen the attachment of protein to linen, though the nature of the forces responsible (ionic? hydrophobic?) remain a matter of conjecture, that being professional code for "I haven't the faintest idea". It's simply easier to see the detached material in clear synthetic detergent than in cloudy soap solution.
To follow: expect some more thoughts re STURP and reasons - entirely predictable in my view- for its largely negative findings. It did not set about its task in a sufficiently bold and imaginative fashion. It relied too much on instrumentation, and overlooked one tiny truism: fundamental science, the sort that deals with new and unfamiliar phenomena that defy explanation, relies upon model building and model testing. STURP tried to operate without a model, bar that uninspired pre-Secondo Pia view that "maybe it's just a painting".
Update: Saturday 30 May 2015
Yes, as I say, there's a quaint idea in some quarters that if you throw enough technology at a recalcitrant problem, it will buckle under the strain and be forced to yield. It worked for the 1969 Moon landing, so why not unexplained phenomena in general that one encounters from time to time in the natural or man-made world? Answer: because science and technology, while complementary, one aiding the other, operate by entirely different methodologies. Science relies upon repeated cycles of hypothesis testing in an attempt to edge towards an answer. Sometimes it works over acceptable time scales, sometimes not. Technology starts by setting a time scale, a target date in order to perfect one or other application of science to achieve a practical end-product. If there's a risk that target date will not be met, then compromises will need to be made, target specifications maybe made less demanding. But there can be no target dates in fundamental science. President Kennedy set a target date for putting a man on the moon, one that was achieved 5 months before the 1970 target date because it was basically a technological goal. However when President Nixon began in 1971 to talk about setting a target date for conquering cancer, the scientific and medical community had to warn him against so foolhardy a step, one that would almost certainly result in the squandering of tens or hundreds of millions of dollars with no guarantee of a successful end result. Put more simply, the scientist needs to have an inkling of underlying process or mechanism in order to know where to concentrate manpower and resources. Without that inkling he or she could waste years or decades thrashing around for an answer, accumulating masses of data that throw little or no light on the problem.
Folk can probably guess where this is leading - to STURP and its technology-obsessed approach to the Shroud, arriving in Turin with all that hardware, but without a single good idea about where to concentrate resources. Indeed. most of its efforts were focused on testing a dud hypothesis, something that should have been plain to see back in 1978, and indeed in 1898, namely that the Shroud might simply be 'just a painting'. How could Secondo Pia's negative image possibly have been 'just a painting'. A negative image implies an IMPRINT, one where the template determines the final image, where there is no obligatory artistic free-hand process at the final imprinting stage. One has a master template - a real person, or maybe just a statue or bas relief- that gives a slave imprint - a tone-reversed negative of the master. Why on earth would an ad hoc task force of scientists and engineers bother to focus so much effort in testing for whether the Shroud was 'just a painting' when the primary objective should have been to deduce the process that resulted in a negative imprint?
STURP's prime focus should have been on deducing (a) the nature of the template and (b) the nature of the imprinting process - whether entirely passive or human-aided. In short, the project should have been one about reverse-engineering.
Late addition: see a posting I did in August 2014 on the subject of reverse-engineering, manufacture of templates by 3D-printing etc.
Reverse engineering requires model-building to test hypotheses, the models being compared with the image density at all points on the TS body image. Without any evidence that the blood or "blood" came from real wounds (there being no imaging of wounds as such in the body image), blood should have been subordinated as a research priority.
The project then resolves itself into addressing a key question: is the negative imprint one that required actual physical contact between linen and template? Are there any image features that could not have been formed if requiring actual physical contact? Where are the crucial regions that serve as tests for a 'contact-only' hypothesis?
The key regions selected for special study should have been:
(a) the neck and underside of the chin here more than one commentator has suggested that the image does not look quite right. If modelling off real person (living or dead) or statue in a medieval forgery scenario, one or more decision would have need to be made regarding the neck.
(b) the gaps between fingers. There is a limit to the contact that can be made when imaging fingers, not only when relying on gravity acting on a loosely-draped cloth, but also when manual pressure is applied. There has to be an element of 'bridging' between fingers, one that cannot be ignored, given the oft-commented upon spindly appearance of Shroud fingers, an important pointer one suspects to imprinting requiring obligatory physical contact. Recognition of the latter would quickly rule out fanciful radiation models, ones that require a mysterious new form of radiation, unknown to science, capable of projecting images across air gaps, provided they do not exceed 3.7cm in width (!).
That's the optics and physics dealt with. Now for the chemistry (and botany): is the image intrinsic to the linen carbohydrates, or is it associated with an extrinsic coating ("impurity layer")? An answer to that question could be (or have been) gained by use of high resolution light or scanning electron microscopy, especially of cross-sections of TS body image fibres. Various mechanical and/or chemical/enzymatic procedures could have been used to remove a putative impurity coating, to see what was underneath - an intact or degraded fibre, with or with its primary cell wall. (Ah yes: the PCW - an entity that somehow fails to receive a single mention in the 1981 STURP Summary despite being the most superficial part of the linen fibre, and despite having a thickness (200nm) that corresponds, approximately, with Rogers' estimate of TS body image thickness).
Overview of STURP's damp squib (no big bang, just a handy smokescreen for some)
Why did STURP set up its straw man target (if you'll pardon the internet lingo), i.e. that it was 'just a painting'? Given all the effort expended in ruling out what should have been self-evident from an imprinted negative image, why did it end up telling us next to nothing positive about the TS image?
If one looks at the research activity of its demob-happy leading lights subsequent to publication of the 1981 Summary, it's clear why the latter took the form it did. It left the road clear for narrative-spinning pro-authenticists to drop any pretence of scientific objectivity, and to go inserting fantasies as if fact into the Shroud literature. I refer to Raymond N.Rogers with his Pliny era special pleading (starch fractions, saponins etc initally, with more later in the pipeline re spliced repair threeads and missing vanillin precursors for challenging the radiocarbon dating), to John Jackson for his wacky radiation-imaging/collapsing cloth ideas, and to Adler and Heller for their "blood too red /trauma bilirubin" fantasies. None of that massive self-indulgence, that wholesale retreat from strict scientific objectivity would have been possible if STURP had done its job properly, and focused on the TS as (probably, indeed almost certainly) a simple contact imprint, one requiring manual assistance, and thus consistent with the radiocarbon dating and medieval forgery.
The stultifying STURP project, with no realistic prospect of a return visit to Turin for years, nay decades, had its intended effect - to create a smokescreen-protected frozen conflict, one in which the pro-authenticity pseudo-science tendency could operate with impunity. Thank goodness that STURP's attempts to oversee the 1988 radiocarbon dating (mixing and matching with a broader-based examination of pre-Lirey "history" was rejected. Just imagine the result: a few pen drawn circles on the Pray Codex - the coffin lid, not Shroud as we are/were led to believe - would have been produced as a trump card, grounds for rejecting that oh-so-arrogant 'error-prone' methodology for which an endless source of contaminants can be invoked - new repair threads, bioplastic films, thymol, radiation-induced C-14, carbon monoxide, smoke ...
Returning to the practicalities, readers of this blog who have been following the new line of investigation (two stage model: flour imprint/nitric acid development) may have noticed the switch from using nitric acid vapour to nitric acid solution, the latter being a lot more convenient. Why was vapour used initially? There were two misgivings: 1. Immersing the flour-imprinted linen in solution might cause the flour to wash off. 2. The nitric acid solution might cause excessive damage to the linen.
My fears proved groundless on both scores. The starch does wash off (or at any rate, some of it) but gluten, being insoluble in water, does not. As regards the linen, yes it does become discoloured, more so usually in solution compared with vapour. But that can be seen as an advantage in a forgery narrative, converting pristine white linen to a more aged appearance. Despite the colour change, the linen is not noticeably weakened (obvious weakening would have precluded nitric acid as a developing agent, while noting that TS linen fibres were found to be mechanically weaker than expected for a 700 year old forgery (Fanti) and to contain less "vanillin" (Rogers, vanillin precursor actually) than expected. Nitric acid development, rather than 2000 years of ageing, might account for either or both of those anomalies.
Update: 30 May, 15:00
Gluten as we have said is rubbery and highly insoluble in water. That's on account of a preponderance of apolar (fat-soluble) amino acid side chains in its structure. One wonders if this might explain why Rogers was able to strip the image layer on TS fibres so easily. He was using custom-made Mylar adhesive tape. The adhesive was a pure hydrocarbon. Like attracts like in chemistry. Might the Mylar tape adhesive have been a compatible environment for the nitrated gluten in the proposed model? Where can I get hold of Mylar tape, or something similar?
Update: 30 May, 19:45
I see my comments regarding STURP have not been well-received elsewhere.
That comes as no surprise, given that site's pro-authenticity posture, and the scorn its commenters (for the most part) and occasionally the site owner too heap on those who dare to question authenticity.
I no longer comment there, considering that to be futile and masochistic. However, it won't stop me expressing candid views here, on my site, on my personal space. If anyone's aggrieved by what I say here, then there's a facility for leaving comments to which I shall try to respond to promptly, provided a civil tone is maintained.
Update: 31 May, 07:30
So, to the question: why are/were we supposed to see the TS image as an imprint, a real imprint, not just an artist's impression of an imprint, the answer, correction , answers, are painfully simple:
1. It's the close correspondence to events leading up to and immediately following Joseph of Arimathea's arrival at the cross bearing expensive linen for wrapping and transporting a sweat and blood-stained body, likely to leave an imprint, stoopid
2. It's the up-and-over double image, on high quality linen, stoopid.
3. It's the life-sized image, stoopid.
4. It's the negative image with 3D properties, stoopid.
5. It's the cardboard cut-out look, stoopid, with no imaging of sides, stoopid.
6. It's the image superficiality, stoopid
7. It's the real-looking bloodstains, stoopid.
8. It's the absence of a loin cloth, stoopid.
9. It's the absence of a crown of thorns, just strategically-sited blood stains in the hair etc, stoopid.
10. It's those spindly fingers, exactly as expected from real imprinting, stoopid
11. Ten killer clues should be more than enough to be getting on with. If you want more than 10, then it's the whole darn shebang, stoopid.
Afterthought (added June 8): there's a genuine No.11 that can be added to that list - the prominent crease at neck/chin level that must surely have been acquired during the imaging process, not after, given the twin-track appearance (dark/light/dark). Paintings on linen don't have creases since the linen would have been stretched out on a frame, like regular artists' canvas. However, creases can easily be formed and trapped when manually moulding linen to relief to capture and imprint an image, especially in places where there's abrupt changes in 3D relief, where chin meets neck etc.
There's a possible No.12 if one's a history buff: words from the shroud.com site attributed to Savoy courtier, Antoine de Lalaing (1503):
"Lalaing adds that the Shroud's authenticity has been confirmed by its having been tried by fire, boiled in oil, laundered many times 'but it was not possible to efface or remove the imprint and image.'"
Even if the story were apocryphal, nobody would dream of doing those things to something that bore even the slightest resemblance to a painting. A faint and mysterious imprint on linen is an entirely different matter.
No.13: imaging of the soles of the feet (dorsal view). No artist would show the underside of the feet as a straight-line continuation of the leg in a painted portrait. Soles of feet say "imprint", with linen needing to have been turned up through a right angle at the heel during the imprinting process and patted (nay, stuck) against the sole by person or persons unknown.
No.14: the break in the image where one hand crosses the other. No artist would have needed to show a break. The break is due to loss of contact between linen and flesh as a consequence of the bridging of linen due to a step-change in height, creating an air gap. No contact: no image.
No.15: a certain subset of the 372 scourge marks on the TS, i.e.Type 1 that have a characteristic dumbbell shaped corresponding to lead pellets, are described as "imprints". Indeed they are, given they are made by blood, not body image. What's more the diameter of the imprints is stated very precisely (0.8mm). No artist would need to separately imprint Type 1 scourge marks, least of all in realistic-looking blood. If the Type 1 scourge marks are imprints in blood, then the entire TS is almost certainly an imprint too - including the sepia-toned body image, despite our continuing ignorance as to the precise chemical nature of the chromophore.
To conclude: to those of us who ain't stoopid (that being a playful and light-hearted rendering of stupid) the Turin Shroud IS a real imprint.
The real question is whether the TS could only have been formed by imprinting of the real Jesus onto his burial shroud, as we are repeatedly asked to consider and/or believe by certain self-styled "scientists", OR whether it could have been faked by a medieval artisan.
This retired scientist's own position, after some 3.5 years of research, albeit in kitchen and garage: of course it could have been faked. My current two-stage imprinting/developing model, which the world of Shroudology is still largely ignoring (Thibault Heimburger MD being a notable exception) - or maybe has yet to learn of - shows how it could have been accomplished, at least in principle. It ain't rocket science. Indeed, it's part kitchen science, starting with plain white flour. Medieval alchemists could have supplied the nitric acid.
Hopefully my model will not turn out to be a damp squib, the way the STURP Summary was a damp squib, with much pseudo-science following in its wake, much of the latter coming from senior STURP members who, in view of their unique STURP credentials should have exercised greater self-restraint, no matter what their particular 'world view'.
End of posting. Comments invited. I now respond to comments here, and here only.