Some Say the Image on the Shroud of Turin was Painted

This page is best understood by first reading the page about Understanding the nature of the Shroud of Turin's images.

We know enough about the image chemistry from spectral analysis to know that the image was not painted.

When it comes to the Shroud of Turin, McCrone’s observation and conclusions are disputed by numerous studies published in peer-reviewed scientific journals. The issue is not authenticity. Rather it is the quality of McCrone’s assessments in light of considerable scientific observation. The overwhelming evidence against McCrone is detailed in several peer-reviewed scientific journals.  

In 1978, Raymond N. Rogers, a chemist at the Los Alamos National Laboratory, collected 32 adhesive sampling tapes from the Shroud of Turin. These tapes were specially designed to be applied with a minimum amount of pressure to collect loose fibers and other particulate matter from the surface of the Shroud. Rogers hand carried the samples from Turin to McCrone in Chicago. They were only to be borrowed and returned. As part of the arrangement, the particulate material was not be pressed into the adhesive by mounting them on glass slides. McCrone ignored the agreed upon protocols. Rogers, accompanied by other scientists, had to travel to McCrone’s lab in Chicago to demand the return of the slides. Much to his dismay, he discovered that McCrone had, in fact, attached the tapes to glass slides. Rogers would later write: 

“Walter McCrone had ignored agreements on how the STURP samples were to be observed, and he contaminated all of our samples by sticking them to microscope slides. All of the fibers were immersed in the tape's adhesive.”

McCrone claimed that there “is no blood in any image area, only red ochre and vermilion in a collagen tempera medium.” Other scientists, including John Heller of the New England Institute and Alan Adler of Western Connecticut State University, having conducted sophisticated tests and not relying merely on microscopic observation, found these claims preposterous. Many of the studies are reported in the journals: Applied Optics, ACS Advances in Chemistry, Archaeological Chemistry, Analytica Chimica Acta and Canadian Society of Forensic Science Journal.  

According to a report on the McCrone Research Institute website, “The faint sepia image is made up of billions of submicron pigment particles (red ochre and vermilion) in a collagen tempera medium. Dr. McCrone determined this by polarized light microscopy in 1979.” 

But polarized light microscopy (PLM) has its limitations. So, too, does individual observation. And these conclusions from McCrone seemed to contradict other findings by several other scientists. To get a more precise chemical analysis, pyrolysis mass spectrometry tests were undertaken at the Midwest Center for Mass Spectrometry at the University of Nebraska, a National Science Foundation Center of Excellence. The results were conclusive beyond any doubt. What McCrone claimed to have found was simply not there. The images were not painted. Other spectra tests were done, as well. Raymond N. Rogers, a chemist and Fellow of the Los Alamos National Laboratory, later wrote:

The Shroud was observed by visible and ultraviolet spectrometry, infrared spectrometry, x-ray fluorescence spectrometry, and thermography. Later observations were made by pyrolysis-mass-spectrometry, laser­microprobe Raman analyses, and microchemical testing. No evidence for pigments or media was found.

Your eye sees colors when the surface absorbs some wavelengths of light and reflects others. A red surface absorbs all visible wavelengths other than red. Each chemical compound absorbs wavelengths that are characteristic of its chemical structure. The best way to determine the properties of a color is by measuring its spectrum.

The reflectance spectra in the visible range for the image, blood, and hematite are shown in the figure. The image could not have been painted with hematite or any of the other known pigments. The spectrum of the image color does not show any specific features: it gradually changes through the spectrum. This proves that it is composed of many different light-absorbing chemical structures. It has the properties of a dehydrated carbohydrate.

Walter McCrone responded. It seemed to be a strange, tilting-at-windmills response. Was he trying to defend his solo visual observations against “two different groups of presumably good scientists” or was he claiming that PLM was unjustly being replaced with newer technology? “I hope something can be done,” he writes, “to convince scientists to use the proper technique and instruments to solve today's analytical problems.” 

I had hoped solving these problems using PLM then using other proper ultramicroanalytical instrumentation for confirmation would help PLM recover its lost position in analytical chemistry. PLM has been cheated out of this recovery and is rapidly sliding into oblivion. This situation is now no longer funny, and I am looking for ways to redress this wrong. It seems to me to be a matter for the attention of the American Academy of Sciences.

The Vinland Map:
Walter McCrone's Other Big Mistake