This seemed to be clear evidence of a carefully crafted repair, intended to not be noticeable.Rogers confirmed the existence of embedded cotton fibers in the area of the carbon dating sample, while noting that such cotton fibers are not found in other samples from anywhere else on the shroud.Finally, and significantly, Rogers found that vanillin had been depleted from the main body of the Shroud but not from the mended corner.This could only mean that the carbon dating sample was not representative of the whole cloth and that the cloth was much older.Gilbert Raes, a textile expert, had first found cotton fibers in 1973.He assumed, and everyone assumed at the time, that this was representative of the whole cloth. Thousands of fiber samples taken from the main part of the Shroud reveal no cotton, whatsoever.The author dismisses 1988 carbon-14 dating tests which concluded that the linen sheet was a medieval fake.
In addition to the discovery of dye, microchemical tests - which use tiny quantities of materials - provided a way to date the shroud.The most plausible explanation for this difference was that material in this area contained threads that had been bleached more efficiently.It was already known from the shroud’s faint variegated appearance that the shroud’s thread was probably bleached before weaving, probably with potash."It was embarrassing to have to agree with them," Mr Rogers told the BBC News website.The 4m-long linen sheet was damaged in several fires since its existence was first recorded in France in 1357, including a church blaze in 1532.
It is said to have been restored by nuns who patched the holes and stitched the shroud to a reinforcing material known as the Holland cloth.