The Turin Shroud is the most famous relic in the world. Millions believe that it is the burial cloth of Jesus Christ bearing his crucified and bloodied image. The cloth is kept at Turin in Italy. The cloth is an enigma. Many say it is a miracle.

David Sox was one of the founders of the British Society for the Turin Shroud in 1977. With that he became its first General Secretary.

Sox wrote File on the Shroud the following year which suggested the Shroud could be real but it stopped far short from saying that was in any way convincing. He made it clear he wanted to believe.

Walter McCrone stepped in in that climate.

McCrone got 32 sticky tapes that had been touched to the shorud to test for different things. Debris stuck to the tapes and could be examined under a light microscope. Ray Rogers provided the tapes on loan. It is said that McCrone falsely claimed that half the tapes were his. He had to give them back and felt he was cheated.

That aside he said he could find no traces of paint.  But he did find iron oxide particles.  There was some trace of mercuric sulfide.  One particle of vermilion was identified.  On that basis we are told that he assumed in a leap of reasoning that the iron oxide residue was red ochre.  He could not find any traces of a binder for this "paint" but did a test for protein which turned positive.  But few think this was really a trace of the gelatin binder.

Against McCrone, it was said that iron oxide appears just as much where there is no image.  They said the exception was the blood areas which they explained by saying it was possibly iron from the blood. 

He said in 1980, "I am not saying the Shroud is not authentic. I am saying that the image area has a lot of iron oxide and a lot of artists' pigment associated with it, but I do not know whether the amount of iron oxide present is sufficient to explain the entire image".

The blood images are too impressive to be really 2000 year old blood!  Visually the paint hypothesis is the best.
All tests showed that it was not blood (page 49, Free Inquiry, Vol 18:2). Two scientists tested the “blood” and found that it was blood but their conclusion was invalidated by the fact that tempera paint could still explain the characteristics they associated with real blood (ibid, page 49). These guys were not qualified for making this analysis (page 27, Looking for a Miracle). At least the Shroudie, Ian Wilson, tells us that there is no proof for blood on the cloth (page 109, The Blood and the Shroud). There is DNA on the cloth but it was touched a lot over the years and cells are always being left behind on the touched item. And if I were going to forge a Turin Shroud I would use some blood in the pain to give it greater authenticity. I think there is blood on the cloth but then our modern science would be able to prove it if there were. Perhaps the amount of blood is so small that tempera paint is the main body of the blood marks.

One excuse for the evidence of paint is that copies were painted and put on top of the shroud.  This is total rubbish.  Second rate relics typically are only touched briefly to the main relic.  For example, a huge cloth can be touched to a saints tooth and that makes the whole crate of cloth a relic.

There was no need for laying out the Shroud on an altar and putting something all over it. Painted copies of the shroud that were touched to it didn’t have enough paint on them to come off to leave a significant reading of the presence of paints on the Shroud. You can see snaps of them in Ian Wilson’s The Blood and the Shroud.

McCrone also found evidence that people had been working on the image to preserve it and make it seem more miraculous during the previous two hundred years (page 48, The Turin Shroud is Genuine). He found that iron particles were being added to make the blood. We will see that this idea of interference with the Shroud is backed up by other pieces of evidence. It may be possible that the Shroud was originally a faint painting but was turned into a kind of photograph in the nineteenth century. We must remember that it was never photographed until 1898 when its properties as a negative were first discovered.

McCrone never said the image is a typical painting.  It clearly is not from visual inspection.  It is a unique technique.