# Shroud of Turin forgery **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 25, 2005, 3:26pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211 "2005-03-25T15:26:01Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 25, 2005, 3:26pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/1 "2005-03-25T15:26:01Z")
Saw this on the news the other night. Now it’s on the Web: [http://story.news.yahoo.com/news?tmpl=story&cid=519&ncid=519&e=5&u=/ap/20050324/ap\_on\_re\_us/shroud\_of\_turin](http://story.news.yahoo.com/news?tmpl=story&cid=519&ncid=519&e=5&u=/ap/20050324/ap_on_re_us/shroud_of_turin) Teacher claims that the Shroud of Turin could have been forged by painting an image on glass, placing it over the linen, and letting it bleach in the sun. **Pepper Mill** , watching this on TV, immediately responded “They didn’t have pieces of glass that big back then.” It doesn’t matter if you think this was forged in 33 AD, 1352 AD, or 1852 AD, the statement still holds true. Float Glass manufacturing, that allowed the production of big pieces of plate glass is relatively recent. I’m surprised that nobody in the news media has brought this up. Joe Nickell, Skeptical Investigator and regular contributor to **The Skeptical Inquirer** published a book giving a way to forge the Shroud over 20 years ago. His method doesn’t require big sheets of glass, or anything else not available to a gorger in the 14th century. No news report has brought this up, either. ---
**Author:** ![Captain\_Gutgore\_Blooddrink](https://avatars.discourse-cdn.com/v4/letter/c/c5a1d2/32.png) [@Captain\_Gutgore\_Blooddrink](https://boards.straightdope.com/u/Captain_Gutgore_Blooddrink)\ **Post date:** [March 25, 2005, 4:24pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/2 "2005-03-25T16:24:11Z")
[Link](http://www.straightdope.com/classics/a2_275.html) to Cecil’s column for story comparison purposes and such. -The Cap’n ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 25, 2005, 5:19pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/3 "2005-03-25T17:19:55Z")
I searched for his explanation on the size of the glass size: [http://www.shadowshroud.com/faq.htm](http://www.shadowshroud.com/faq.htm) > [@](#): > > **How big was medieval glass? Could they make big pieces, or were they all little like those in stained-glass windows?** > Wilson’s answer: > When I first presented the Shadow Theory, tentatively, to the student body of New St. Andrews College, I did not know the answer to this question. A member of my audience, however, did. As she had worked a great deal within an artisan glass shop that still used medieval technique she was able to describe the method for blowing a sheet and told me that sheets measuring 6’x8’ were fairly common. When I looked into her explanation, before experimenting, I found that she was absolutely right. Throughout the thirteenth century glass blowers were capable of creating large sheets. They would blow cylinders, up to nine feet or more in length and then, while the glass was still molten enough, they would cut off the bowls that formed both the top and the bottom and slice the cylinder lengthwise, unfolding it into a sheet. The sheets would be cut into small pieces for use in leaded stained-glass windows, or painted while large. > As the Shroud is roughly fourteen feet in length, two pieces of glass would be necessary, both at least six feet long. The image of the front of the man would be produced beneath one and the back of the man beneath the other. > > When Dr. Antonio Lombatti, Fellow Researcher in Medieval Church History at the Deputazione di Storia Patria in Parma, Italy was recently asked about the availability of glass large enough to produce the Shroud, he responded, “Of course a medieval artist could have enough glass to produce that relic.” He pointed out that six foot painted glass windows were not uncommon, and also mentioned that the length discrepancy between the front and back images of the man in the Shroud (1-2 inches) suggests two different phases of production. > > \*\*So, medievals could blow glass sheets large enough for this process, but were they clear enough? Wouldn’t the glass be flawed? How about other materials? Would an image made in sand directly on the cloth, or a thin painted fabric laid out on the linen have the same effect? \*\* > Wilson’s answer: > :Medieval glass, particularly Venetian, would have been plenty clear enough to allow for light penetration (it wouldn’t need to be clear enough for us to watch the hummingbirds in the front garden). That is the first necessary step. As far as flaws go (wavy surface, air bubbles, etc.) at this point I can only extrapolate based on what I’ve seen thus far in my experiments. As I first began work painting images on glass, I soon realized that the sun’s path was important for more than just the three-dimensionality of the image. My paintings, and those of the people helping me, were all positively cluttered with brush-strokes, and brush-strokes are not visible on the Turin Shroud. The theory went this way: as the sun travels it will expose every brush-stroke from a mathematically infinite number of points. The distinct shadow created by a brush-stroke would be dispersed along a line in reverse of the sun’s path. In addition, the sun’s route would shift a degree or two (or three, depending on the amount of time the linen was exposed), and the smoothing out of the brush stroke (and the linear path of that dispersal) would spread out in width as well. The cloth that was exposed beneath a sun lamp was used as a control for just this reason. When exposed beneath a stationary light source, the crudeness of the image remains, or worsens (with brush strokes visible). When the same image is placed over cloth beneath a traveling sun, the strokes disappear and the image becomes fluid. This same process would occur for flaws or waves in the glass. Some of the chunky spots on the painting I used are far more drastic than a glass flaw, and yet they are invisible in my image. Also, due to the proximity of the cloth to the glass (flush beneath it), potential refraction of light due to waving, would become negligible. Even more so because of a traveling sun. > > As far as sand on the cloth is concerned, an image would certainly be created, but it would not be three-dimensional as there would be no gap between the sand and the cloth to allow for the sun’s path to shift and sculpt the shading. A thin cloth would work, and is something that I have discussed with several people at times. It would only work if it were stretched tight over a frame (to create the necessary distance between the painting on its surface and the linen beneath it). The frame itself could not be too tall, probably no more than one half, to three-quarters of an inch. However, I find glass more natural and believable to a medieval forger. For one, glass accounts better for those never mentioned wrinkles on the cloth. There are regular constellations of wrinkles on the Shroud that predate the image-formation (there is blood in at least one of them). These wrinkles are generally the same color as the image on the Shroud, but occasionally appear darker. In the shadow theory, if a wrinkle were trapped beneath the glass, the linen within would be as protected, or more, as that beneath the painted portions. The result is a dark image, but also many dark wrinkles. I have yet to encounter any other explanation for these wrinkles, though there may be one. > > In the end, like my initial testing of this image-making process, I can’t know exactly how linen will react beneath medieval glass until I actually test it, something I hope to do this summer. However, I believe what I’ve learned from the disappearance of my brush-strokes, will apply equally well to glass flaws. IIRC, proponents of the camera obscura explanation mentioned that the head of the figure is separated from the body, that created problems for the pseudo photograph explanation of the shroud, because there is no reason to “develop” the body and then the head separetely as the proponents of the camera obscura theory have to say to make that flaw fit their theory; but this new theory fits nicely with that floating head flaw: obviously several sheets of glass were used at the same time by the forgers. There was no need for a very large flat pane. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 25, 2005, 5:32pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/4 "2005-03-25T17:32:33Z")
One extra size on the last post! :smack: Even Steven Schafersman from the Skeptic thought that this new explanation was flawed, but is looking that it is stronger than at first glance: [http://www.skeptic.ws/shroud/articles/rogers-ta-response.htm](http://www.skeptic.ws/shroud/articles/rogers-ta-response.htm) > [@](#): > > Nate D. Wilson contacted me by email to explain that he meant that his positive image was a “true photonegative” of his re-created negative Shroud image, not that this image on the bleached cloth was a true photonegative. In this he is perfectly correct. I thank him for clarifying the matter, and I regret the misunderstanding. > > I emphasized the alleged photonegative aspect of a Shroud image because the Shroud authenticity advocates insist that the Turin Shroud is a true photonegative, a historical anomaly, therefore suggesting it is unprecedented or miraculous, when in fact it nothing of the kind. The final positive images of the Turin Shroud and Wilson’s re-creation are not true photopositives, even though they are both true photonegatives of their respective original negative images, because the original images are not true photonegatives. The Shroud face in a positive image looks remarkably lifelike, but the resemblance is superficial. The image is not only monochromatic, like a photo of a human face in shadow or a dark room, but the shading of features is unrealistic (dark hair is light, etc.), because the image was not reproduced by a photographic process, but by an artistic one. Wilson’s method accurately reproduces the Shroud image because his method uses artifice, not photography. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 25, 2005, 6:06pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/5 "2005-03-25T18:06:05Z")
**Gigobuster** , that’s an extremely interesting post. It contradicts everything I’ve heard about Medieval (and since) glass production, and now I gotta look into it. Because I’ve _never_ seen large pieces of glass from anytime more recent than the past 150 years or so. Everyone who’s ever lectured or written about it (that I’;ve encountered, at least) says that the classic glass-making method was to basically blow a large balloon of glass, then puncture it and spin. The glass forms a disc shaped. You keep spinning it until it cools. There’s a noticeable thickness difference between hubward and edgeward, but you put all the pieces in place with the prism going the same way, so people don’t notice. (remember all the discussions about whether glass flowed or not, based upon the greater thickness at the bottom?) But this, everyone says, is the reason that windows were made up of lots of small pieces of glass – large ones simply didn’t exist. I’ve never heard of this cylindrical method before. As for the glass being transparent enough – that I really find hard to buy. Even up until the beginning of the 19th century glass was full of striae and bubbles, especially in (relatively) large pieces. Faraday and his committee to make better optical glass dates back to almost that time. Sheets 6’ X 8’ were _common_? I’ve never heard of a piece of centuries-old glass anywhere approaching that size. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 25, 2005, 6:14pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/6 "2005-03-25T18:14:55Z")
A f’rinstance of what I was raised on: > [@](#): > > Flat glass for windows was still rare during much of the 17th and 18th centuries. Small panes were made by blowing a large glob of glass, removing it from the blowing iron and then rotating the glass quickly so it would spread and flatten. Such glass had a dimple in its center, many air bubbles and a pattern of concentric circles, but it was transparent and effective in keeping out the weather. At the end of the 17th century, the French learned how to grind and polish cast glass to produce plate glass, but only the rich could afford it. > > During the 1800s, glass technology improved rapidly. A hand-operated split mold developed in 1821 that ended the age of blowing individual bottles, glasses and flasks. A semi-automatic bottle machine perfected 50 years later mass-produced bottles and turned them into the everyday miracle they are today. > > Great strides were made in the manufacture of flat glass during the 19th century. Compressed air technology led to flatter, better glass panes. Controlled amounts of air were used to blow a large glass cylinder, which was slit lengthwise, reheated and allowed to flatten under its own weight. Large, relatively inexpensive lites of glass were produced in this manner. As a result of such technological advances, window areas that required 18 to 24 panes to enclose in 1730 could be increased dramatically and glass prices dropped by the 1860s, glass-enclosed “wind eyes” were commonplace in the humblest homes. > > Plate glass, that wickedly expensive French product, also became commonplace by the end of the 19th century. Water power, then steam and then electricity made the grinding and polishing of heavy glass plates faster and easier. By the 1860s, smart stores and office buildings in Europe and North America glistened with plate glass. France, Belgium and Germany monopolized the production of the product until 1883, when the Pittsburgh Plate Glass Company became the first successful manufacturer of the product in the United States. By 1895, the company could produce 20 million square feet of plate glass a year, and imports from Europe fell sharply. This is from Pittsburgh Plate Glass’s own site. [http://www.glasslinks.com/newsinfo/histppg.htm](http://www.glasslinks.com/newsinfo/histppg.htm) Or look at this site (especially the pix): [http://www.londoncrownglass.co.uk/History.html](http://www.londoncrownglass.co.uk/History.html) This Lombatti and St. Andrews stuff is news to me. And I just want to point out that I’ve got a degree in Optical Engineering – we studied the history of glassmaking. This stuff, if true, isn’t widely known. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 25, 2005, 6:16pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/7 "2005-03-25T18:16:20Z")
Hmm. There is this: > [@](#): > > Sheet glass skills > The 11th century also saw the development by German glass craftsmen of a technique - then further developed by Venetian craftsmen in the 13th century - for the production of glass sheets. By blowing a hollow glass sphere and swinging it vertically, gravity would pull the glass into a cylindrical “pod” measuring as much as 3 metres long, with a width of up to 45 cm. While still hot, the ends of the pod were cut off and the resulting cylinder cut lengthways and laid flat. Other types of sheet glass included crown glass (also known as “bullions”), relatively common across western Europe. With this technique, a glass ball was blown and then opened outwards on the opposite side to the pipe. Spinning the semi-molten ball then caused it to flatten and increase in size, but only up to a limited diameter. The panes thus created would then be joined with lead strips and pieced together to create windows. Glazing remained, however, a great luxury up to the late Middle Ages, with royal palaces and churches the most likely buildings to have glass windows. Stained glass windows reached their peak as the Middle Ages drew to a close, with an increasing number of public buildings, inns and the homes of the wealthy fitted with clear or coloured glass decorated with historical scenes and coats of arms. [http://www.glassonline.com/infoserv/history.html](http://www.glassonline.com/infoserv/history.html) ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 25, 2005, 6:20pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/8 "2005-03-25T18:20:55Z")
I;m impressed. Large sheets were possible, but I don’t think I’d call them common (that last article I cite gives a size considerably smaller than 6’ X 8’). I’ll have to amend my criticism from saying it’s an impossible stunt to a ludicrously expensive one. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [March 25, 2005, 6:24pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/9 "2005-03-25T18:24:05Z")
I don’t see why one would need a single large pane of glass. Couldn’t it have been done in steps, with smaller panes of glass? Paint the top 1/4 on a pane of glass, put it in the sun over the top 1/4 of the shroud, cover the rest of the shroud so it’s not exposed to the sun. After the 1st 1/4 of the the image is bleached to satisfaction, do the same with the next 1/4 of the shroud, with the next pane of glass that was painted with the next 1/4 of the image. Etc. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 25, 2005, 6:35pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/10 "2005-03-25T18:35:25Z")
Well **CalMeacham** , that would also fit why this image could not be easy to reproduce then and so it was seen as a miracle, the technique was, as the makers found, a very expensive process for the day. Also, don’t forget that IMO some imperfections and gaps in the image can be explained by smaller sheets put side to side to create the composed image, the distance that the panes (or thin cloth as he also proposes) makes the shadow fuzzy and hides many flaws, like glass gaps, bubbles, imperfections and more importantly: brush strokes. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [March 25, 2005, 6:57pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/11 "2005-03-25T18:57:24Z")
> [@](#): > > so it was seen as a miracle This technical discussion of the _technique_ is really interesting, but it has been known to have been _identified_ as a forgery at least since 1389, (and was ordered not displayed on the grounds that it was not a true image 30 - 35 years earlier), the wishes of the masses notwithstanding. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [March 25, 2005, 7:10pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/12 "2005-03-25T19:10:29Z")
**tomndebb** , sorry I was not clear enough there: I am here talking about a miracle in the sense of “One that excites admiring awe. See Synonyms like wonder.” And it refers to the, until now, mystery of how it was indeed made by human hands. ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [March 26, 2005, 2:25am UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/13 "2005-03-26T02:25:46Z")
> [@CalMeacham](#): > > I;m impressed. Large sheets were possible, but I don’t think I’d call them common (that last article I cite gives a size considerably smaller than 6’ X 8’). I’ll have to amend my criticism from saying it’s an impossible stunt to a ludicrously expensive one. But given that relic sales were a quite lucrative industry in the Middle Ages, perhaps still a profitable stunt. ---
**Author:** ![astorian](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@astorian](https://boards.straightdope.com/u/astorian)\ **Post date:** [March 26, 2005, 3:03am UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/14 "2005-03-26T03:03:55Z")
> [@CalMeacham](#): > > ely recent. > I’m surprised that nobody in the news media has brought this up. Why WOULD the media bring it up? As Tom notes, Catholic Church authroites called the Shroud “a clever hoax” as far back as the 14th century. More recently, carbon 14 testing has proven pretty conclusively that the Shroud isn’t nearly old enough to have been used for the burial of Jesus 2000 years ago. So, while knowing exactly HOW the original artist created the effect is sort of interesting to some of us, I can see why most media outlets would read the latest speculation (and so far, that’s ALL it is- interesting speculation) and shrug “So what? We already know the Shroud is a fake. That’s old news.” ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [March 26, 2005, 3:57am UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/15 "2005-03-26T03:57:59Z")
> [@Revtim](#): > > I don’t see why one would need a single large pane of glass. Couldn’t it have been done in steps, with smaller panes of glass? probably not, or not as well as it was done. Getting an even exposure would be extremely difficult and you would see hard lines where the panes connected. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [March 26, 2005, 1:22pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/16 "2005-03-26T13:22:21Z")
> [@dropzone](#): > > probably not, or not as well as it was done. Getting an even exposure would be extremely difficult and you would see hard lines where the panes connected. Maybe I didn’t explain it well enough, but you wouldn’t need the panes to be connected. You would do one pane at a time, so there’d be no connections between the panes. Spend a week (or whatever) with one pane exposed and the rest of the shroud covered, then expose the next section with the next pane, covering the rest of the shroud, etc… ---
**Author:** ![bizzwire](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bizzwire](https://boards.straightdope.com/u/bizzwire)\ **Post date:** [March 26, 2005, 6:21pm UTC](https://boards.straightdope.com/t/shroud-of-turin-forgery/296211/17 "2005-03-26T18:21:00Z")
**Cal,** I think part of your problem is that you are confusing the _capability_ of producing large sheets with the ability to do it for large-scale consumption. The former has been demonstrated to exist in the 13th Century. The later, as you have pointed out, is a recent development. Also, why would the glass have to be perfectly flat, clear, and/or free of bubbles; for this application? The objective was not to see perfectly through it.