Drawing on a method previously used by skeptics to attack authenticity claims about the Shroud, Science & Vie got an artist to do a bas-relief — a sculpture that stands out from the surrounding background — of a Christ-like face.
A scientist then laid out a damp linen sheet over the bas-relief and let it dry, so that the thin cloth was moulded onto the face. Using cotton wool, he then carefully dabbed ferric oxide, mixed with gelatine, onto the cloth to make blood-like marks. When the cloth was turned inside-out, the reversed marks resulted in the famous image of the crucified Christ.
Gelatine, an animal by-product rich in collagen, was frequently used by Middle Age painters as a fixative to bind pigments to canvas or wood.
The imprinted image turned out to be wash-resistant, impervious to temperatures of 250 C (482 F) and was undamaged by exposure to a range of harsh chemicals, including bisulphite which, without the help of the gelatine, would normally have degraded ferric oxide to the compound ferrous oxide.
The experiments, said Science & Vie, answer several claims made by the pro-Shroud camp, which says the marks could not have been painted onto the cloth.
For one thing, the Shroud’s defenders argue, photographic negatives and scanners show that the image could only have derived from a three-dimensional object, given the width of the face, the prominent cheekbones and nose.
In addition, they say, there are no signs of any brushmarks. And, they argue, no pigments could have endured centuries of exposure to heat, light and smoke.
For Jacques di Costanzo, of Marseille University Hospital, southern France, who carried out the experiments, the mediaeval forger must have also used a bas-relief, a sculpture or cadaver to get the 3-D imprint.
The faker used a cloth rather than a brush to make the marks, and used gelatine to keep the rusty blood-like images permanently fixed and bright for selling in the booming market for religious relics.
To test his hypothesis, di Costanzo used ferric oxide, but no gelatine, to make other imprints, but the marks all disappeared when the cloth was washed or exposed to the test chemicals.
He also daubed the bas-relief with an ammoniac compound designed to represent human sweat and also with cream of aloe, a plant that was used as an embalming aid by Jews at the time of Christ.
He then placed the cloth over it for 36 hours — the approximate time that Christ was buried before rising again — but this time, there was not a single mark on it.
“It’s obviously easier to make a fake shroud than a real one,” Science & Vie report drily.
As to all of Porter's chemical complaints: I was not trying to prove that the Shroud of Turin was faked using this method (though I believe it to have been). I don't yet have the data to make that sort of claim (if I ever will). I set out to prove something with a relatively narrow hypothesis, and I proved it.A medieval could quite simply create a three-dimensional photo negative on linen (even superficially) like the image on the Turin Shroud, without using paints, chemicals, or dyes. Whether the chemical attributes of a cloth exposed this way matches the chemical properties of the Shroud, remains to be seen.Therefore he did not "recreate" the shroud. In addition, he also started with an idealogical bias and that overshadows any results he derived from the experiment. That is just shoddy science. And his answer to #5 about why there are not more cloths from that period like this is hilarious.
As for Jacques di Costanzo, he is not considered to be an expert in this field by those who are and his experiment is also an unproven theory and not a true recreation of the Shroud. Got any other gooey crap you want to try to stick to the wall?
Maybe this will refresh your memory.
Point-by-point discussion of how the work quoted in Science & Vie (not peer-reviewed, despite your insistence on such, btw; how's the double-standard working out for you?) only addresses strawman issues of previous attempts at making an image on cloth, and does not mimic any of the physical or chemical properties of the *real* Shroud.
Cheers!
there is also forensic confirmation up the ying yang - that testifies to the fact that the image is NOT paint, that the ‘blood’ is real blood - that the linen is from the right time and place, that the plant biology proves the linen was in the Jerusalem area and in the correct time frame, - etc etc...
Then there's the provenance via art: Iconic paintings done hundreds of years before the atheists would like us to believe, show that the artists took their depiction of Jesus straight from the Shroud - many even paint in 3 little wisps of hair on the forehead...that appeared to them to be hair - but are, in fact, blood. But those little wisps, painted in the iconic paintings, are proof that the Shroud was in existence and available very early on.
Sorry that the preponderance of evidence for authenticity is 'inconvenient' - The atheists continue to grind their teeth - pretty pointed by now