Modelling the Man on the Turin Shroud using medieval technology: are we nearly there yet?

Site banner: see how a simulated sweat imprint (my wet hand pressed down onto dark fabric) responds magnificently to 3D-rendering computer software (ImageJ) before and after tone-reversal (negative back to positive image). Remind you of anything? Like those supposedly “unique”  and “encoded” 3D-properties of the Shroud of Turin body image? For a more realistic aged/yellowed sweat imprint, see the many postings on this site since 2014 obtained with the aid of my Model 10 (imprinting off  parts, notably head and hands, of a real body (mine!) onto linen with white wheaten flour, followed by heat-development of the image to generate carbon-based and thus bleachable straw-coloured melanoidins via Maillard reactions between wheat proteins and reducing sugars). 

Here’s an update on my 4 years of progressive fine-tuning of the much-maligned “scorch hypothesis”. It’s  a single photograph, obtained just an hour ago, but as I say, some 4 years of work have gone into producing it.

DSC02322 before v after washing

No, it’s not linen, it’s cotton. What’s more it’s pre-baked cotton. Why those particular conditions? Answer: because they generate a result that is simple and straightforward to perceive, with no straining of the eyes, no asking to take anything on trust.

What you see are contact imprints, before and after washing with soap and water, obtained from those two metal  bas relief templates (“horse brasses”). The washed images are the cut-outs closer to the horse brasses (extreme left for prancing horse, extreme right for King George VI).

No, they were not heated and pressed onto the fabric. That’s “old” Mark 1 technology.

No, the templates were smeared with olive oil, dusted with white flour (wheat), then draped with wet fabric that was pressed down to obtain a flour imprint. The imprinted fabric was then heated in an oven to approx 200 degrees C to obtain the image. The latter, presumably formed by a Maillard browning reaction (like toasted bread)  survived washing with soap and water in the case of cotton. (Had linen been used the washed image would have been much, much  fainter – more  Shroud-like one might say).

As I say, conditions have been chosen to give a photogenic result with a simple hand-held digital camera.

No, the images do not fluoresce under uv light, unlike the lettering from the marker pens. That needs to be said, to counter the hoary old chestnut that all “scorch” images fluoresce under uv light. Oh no they don’t (see previous postings), neither the thermal-imprints seen here, obtained by oven roasting, nor direct scorch imprints obtained directly in a single step (by heating a metal bas relief template and pressing down onto fabric to get a classical scorch).

Take away message: while the Shroud of Turin is a tone-reversed negative, as per a photographic negative, its production in medieval (14th century) France would not have required anachronistic light photography.  Negative images are obtainable by contact-imprinting, as shown here.

Profound apologies if I’m destroying mystique or fond illusions, but there’s been far too much over-hyping of the Turin Shroud, much it coming from agenda-driven scientists and technologists (more often the latter) who should know better (or capable of keeping their science and their religion in separate mental compartments). There’s a sense in which both science and religion are mental constructs. That’s no reason to assume they are facets of a single unified mental construct. The brain is known to have two halves. Maybe it has quarters, eighths etc too.

Postscript: added Aug 27, 2020

Here’s a list of the 10 models developed by this retired scientist, each reported online via this and other websites as a “learning curve”. It was originally displayed in the right hand margin of the Home Page, but I’ve decided it’s now largely of historical value only.

It’s been copied and pasted “as is” from the margin.

My 10 experimental models, 2011-2015

Model 1. “Thermostencilling” (the one and only radiation model, quickly dismissed as impractical).

See this from Dec 2011:

Model 2: Direct one-step scorching off a heated metal template, with nothing else apart from linen. (Finally abandoned for mainly practical reasons, but it gave valuable insights into the 3D properties of thermal imprints).

See this from Nov 2013.

Model 3: as above, with coatings, notably WHITE FLOUR (an early  forerunner of the final Model 10!).

I had initially tested starch, glucose etc , surprisingly with little success. it may have been this which sowed the idea that there needed to be something else present. Ray Rogers’ focus on Maillard reactions helped, albeit substituting protein for his volatile putrefaction amines.

See this from Oct 2014:


Model 4: Wet imprinting with natural dyes, notably tannins, with added viscosity agents, essentially as described by Joe Accetta.

See this from March 2015

Model 5: sulphuric acid, flagged up by any number of previous investigators – Luigi Garlaschelli, Joe Nickell among others, the idea being that acids might have etching/discoloring effect on linen.

Result: negligible discoloration, profound weakening of fabric at ordinary temps, no obvious coloration without applied heat.

See this from April 2015:

Model 6: Substitution of nitric for sulphuric acid, first with plain linen, then WHITE FLOUR -coated linen (another forerunner of final model 10).

Probably the most informative experiment of all, assisted by critical input from Adrie van der Hoeven, inasmuch as protein was implicated as a potential source of image chromophore, focussing initially on the traces of protein intrinsic to linen, then moving onto extraneous sources of protein coating, then finally dispensing altogether with nitric acid as developing agent, and replacing with OVEN-HEATING TO PRODUCE MAILLARD REACTIONS. (Yes, Maillard reactions: an echo there of Rogers, but in his pro-authenticity thinking, he had perforce to introduce some less probable sources of amino nitrogen and reducing sugars (decaying corpse and 1st century technical starch or soap coatings as a somewhat improbable source of reducing sugars).

See this from May 2015:

Model 7: quicklime. A longshot, using the highly exothermic reaction between calcium oxide, CaO and water as source of in situ heat, but quickly abandoned.

See this from June 2014:

Model 8: Lemon juice and heat, with its ascorbic acid (not citric acid) as the active ingredient – basically invisible ink methodology.

Probably operates via a Maillard reaction between (a) a constituent 4- carbon reducing sugar – threose – derived from thermal decomposition of ascorbic acid- and (b) amino compounds.
Most of the existing literature assumes (wrongly!) that it’s the linen that discolors when treated with acid, even weak organic ones like those present in lemon juice (citric, ascorbic etc)
See this from October 2014:

Model 9. Imprinting with WHITE FLOUR in the form of slurry then OVEN-ROASTING. Criticized for giving imprints that were too well-defined at edges.

See this from June 2015:

Final 10 (phew!)  Imprinting with dry WHITE FLOUR onto wet linen, followed by OVEN-ROASTING of the imprinted linen. Fuzzier imprints, negative, 3D response in ImageJ software, right thread and fibre properties at the microscopic level – i.e. halftone effect, discontinuities etc. Eureka!

See this from Aug 2015:



About Colin Berry

Retired science bod, previous research interests: phototherapy of neonatal jaundice, membrane influences on microsomal UDP-glucuronyltransferase, defective bilirubin and xenobiotic conjugation and hepatic excretion, dietary fibre and resistant starch.
This entry was posted in contact imprint, Shroud of Turin, Turin Shroud and tagged , , , , , , . Bookmark the permalink.

2 Responses to Modelling the Man on the Turin Shroud using medieval technology: are we nearly there yet?

  1. Colin Berry says:

    It’s naughty and probably unwise to blow one’s own trumpet, but I’m frankly amazed at the quality of those images, especially the one on the right (the king’s head). Using simple materials – metal castings, olive oil, white flour and an oven one can obtain images that while blurry could be mistaken for 19th century photographic negatives. What’s more, they are not necessarily my best images that are obtainable from those two horse brasses. I had started yesterday substituting rice for wheat flour as imprinting medium, leaving an area of the fabric (linen and cotton) free of imprint that could be removed after oven-baking and tested for its ability to take a fresh imprint after that pre-baking step. Yes, images were obtained with the rice flour onto the unbaked linen and cotton, though not as good as MIGHT have been seen with wheat flour. In other words, wheat flour has still to be tested on all four combinations of wheat/cotton/unbaked fabric/baked fabric. The image in this posting was from just one of those 4 (wheat/baked cotton).

    Today I shall test all 4 combinations in the same session, and see which gives the best result. Regardless, one has a technology that delivers results that are reminiscent of those obtainable when bas relief objects cast in metal, or carved into softer materials – lino, raw potato even- are used in conjunction with paint as a means of printing images (as with modern day T-shirts). The difference is that mine is a thermal imprinting technique that appears to produce a final image that is chemically bonded onto the heat-resistant cellulose fibres of the fabric, at least some being resistant to washing with soap and water. Might we be seeing here the technology that was deployed in the 14th century to produce the image of the man on the Shroud?

    More work is needed to characterize that final wash-resistant image, whether obtained on linen or cotton, used ‘as-is’ or pre-baked, and to try and understand the mechanism by which the colour migrates from the roasting flour with its ongoing Maillard reactions into the underlying weave of the fabric. Might oil play a role in the migration, as suggested previously by this investigator last year when first reporting on the flour-imprinting model? That model seems to me to be gaining in strength and hopefully credibility with each passing day, but there will be no counting of chickens, not just yet anyway.

  2. Colin Berry says:

    This comment (from moi, the site owner) has been tacked onto the end of this ancient (Jan 2016) posting.

    Why you may ask?

    It now carries, as a postscript, a list of all 10 models that I developed in the 4 years between start 2012 and end 2015 approx, culminating in the final 3-stage flour-imprinting Model 10. (The earlier hard-to-part with Model 2 – direct scorching off a heated statue or bas relief template – was at first sight simpler – being one-stage only! But see below re the problems it posed as regards visual monitoring of colour development…)

    Model 10 reproduces a TS-like body image as follows.

    First there is contact imprinting from human anatomy – including the face and nose – using solid white flour transferred onto wet linen.

    There is then the second stage heating step of the entire imprinted linen, needed to develop the yellow/brown body image (“Maillard browning products”).

    Finally, there’s the final washing with soap and water to leave a faint, negative image, one that responds magnificently to tone inversion, 3D-rendering software (ImageJ) as per TS. The question as to whether the body image can truly be claimed to be ultra-superficial, confined we’re informed to the PCW of the linen fibre, is addressed in this site’s final posting (see Home Page if not already there).

    Model 10 had an additional big practical advantage over earlier much-favoured candidate Model 2 (direct scorching from a hot statue or bas relief). One can watch the progress of colour development from minute-to-minute at the heating stage, and stop at any point one considers the optimum time. (Compare that with Model 2 direct scorching where one can only guess at the colour of the scorch being formed out of sight UNDER the light-blocking metal template!). Oh, and the template per se doesn’t need to be heated, meaning one can imprint off – guess what?- yes – HUMAN ANATOMY – a hand, a face or even, wait for it, an ENTIRE BODY – front, back or BOTH! But not sides as well. (Ring any bells?).

    The added 10-stage chronology list was previously taking up valuable space in the right-hand margin of the Home Page, but being now largely of historical interest has been moved to the archives! I may do some more rearrangement in due course, if only to improve ease of site-download and/or make the site a little friendlier towards small-screen smart phones etc as distinct from computer laptops.).

    Here btw is how I reported my first ever flour imprint back in October 2014, using a horse brass smeared with oil, then dusted with white flour as template, and merely holding the imprinted linen over a cooker hob:

    Impact on mainstream ‘sindonology’? Answer: essentially zilch! But see my slimmed-down side bar for the two conflicting definitions of sindonology!

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