Medieval Repair
The possibility that the Shroud sample used for radiocarbon dating could have been taken from a corner which had been repaired or patched became a topic of discussion amongst some researchers in the months following the announcement of the radiocarbon dating results. However, it was several years later that this hypothesis began to be taken seriously, largely as a result of research by Joe Marino and Sue Benford.
Their premise was that the sample dated by the three radiocarbon laboratories contained a patch of sixteenth century material that had been skilfully and invisibly spliced into the original Shroud cloth by expert textile restorers employed by the wealthy Savoy family. The fabric tested by the laboratories therefore contained first and sixteenth century material in proportions that produced a medieval date measurement.
This claim of a possible reweave was supported by evidence from three independent textile specialists who analysed photographs of sample, without being told that it was material from the Turin Shroud. They each confirmed that there were unexpected differences between the weave on the left and the right of the sample which indicated they were woven independently, or that part of the sample was a patch. STURP chemist Alan Adler had also discovered that the chemistry of fibres from the radiocarbon area was significantly different to those from the main body of the Shroud.
Analysis by Ray Rogers
In 2002, STURP chemist Ray Rogers published a research paper which outlined his findings after comparing Shroud material taken from the main body of the cloth with threads from the so-called Raes sample, which came from an area immediate adjacent to the radiocarbon cutting. This study produced a number of additional observations which appeared to indicate that the sample area was not the same as the rest of the Shroud, including:
- The outer fibres of the Raes threads showed a yellow-brown encrustation but there was no such coating on fibres from the main body of the Shroud. Rogers believed it consisted of a plant gum and Madder root dye which had been applied to these threads to match the colour of the Shroud fabric.
- One of the Raes threads appeared to have been spliced to join the ends of two different threads. He had not found similar splices on the main body of the Shroud.
- He was able to find vanillin in the Raes threads, which is a substance that disappears from flax fibres over time, but no traces of vanillin were found in the main body of the Shroud
He also analysed ultraviolet photographs of the Shroud that had been taken by the STURP team which showed that the fluorescence in the radiocarbon sample area was much lower than the surrounding cloth. This indicated a different chemical composition.
However, not everyone has been convinced by this evidence. When the radiocarbon sample was taken in 1988, textile specialists Franco Testore and Gabriel Vial were involved in the selection of the sample area. They insist that they had found no evidence of any repair, or splicing of threads, when they examined that area of the cloth. Another textile specialist, Mechthild Flury-Lemberg, also examined that area of the cloth when undertaking conservation work on the Shroud in 2002 and she also refuted claims that there was evidence of a repair. Others have also claimed that transmitted light and X-ray photographs of the Shroud taken in 1978 give no indication of any discontinuity in the weave that would be expected if it had been repaired.
The following links provide further information on the Medieval Repair Hypothesis
Evidence for the Skewing of the C-14 Dating of the Shroud of Turin Due to Repairs. A paper by Joe Marino and Sue Benford presented at the Sindone 2000 Orvieto Worldwide Congress (2000)
Scientific Method Applied to the Shroud of Turin. A research paper by Raymond N. Rogers and Anna Arnoldi (2002)
Studies on the Radiocarbon Sample from the Shroud of Turin. A research paper by Raymond N. Rogers published by Thermochimica Acta Vol. 425 Issues 1-2 (2005)
Discrepancies in the Radiocarbon Dating Area of the Turin Shroud,. A paper by Sue Benford and Joe Marino published in Chemistry Today, Vol. 26, No. 4, pp. 4–12.(2008)
