The carbon dating by the three ASM labs in Oxford, Zurich, and Arizona were accurate... on what they tested.
However, what they tested was not 100% original Shroud material but rather a melange of skillfully rewoven old original Linen and newer Cotton material from the 16th Century.
Photograph of the Zurich C14 Sample
showing suspicious changes in thread width
This hypothesis has now been shown conclusively to be the case in peer-reviewed AND duplicated science. In fact, that is main subject of the documentary being reviewed in the above article.
One side of the tested sample was made of un-dyed, natural Linen (a product of the Flax plant) but the other side, and a portion mixed with old un-dyed Linen in the re-weaving area, is made entirely of dyed-to-match Cotton. between these two areas of pure Linen and pure Cotton is an area of varying width of threads of both materials that have been skillfully spun together to join them invisibly and rewoven to match the original three over one herringbone pattern of the Shroud.
End to End spliced thread from C14
Test Sample area showing inter-twining
of Cotton (L.) and Linen (R.) fibers
The so-called textile expert Mdm. Fleury-Lemberg (the same one who orchestrated the disastrous 2002 "restoration" of the Shroud) claims she has examined the area where the patch was taken and says she "finds no evidence of any darning", which would, according to her, "show threads hanging on the backside of the Shroud." She further claims that the technique of "French Invisible Reweaving" does not, and never did exist. Unfortunately for Mdm. F-L, a small volume titled The Technique of French Invisible Reweaving," published in 1954, demonstrating the technique (which is STILL being done by fine art restoration specialists today) long before the now proved theory that such a technique had been used to repair the corner of the Shroud where the C-14 sample was taken was proposed in 2000. In addition, her assertion that she would see the "darn" demonstrates here complete lack of knowledge of the technique.
The Carbon 14 labs did excellent work... but ignored the red flags. The major red flag was that the tests of four subsamples of a supposedly homogenous item, which should have reported dates well within the margin of error of the testing (+/- 25 years or so) instead were spread over more than 190 years... 1235AD, 1246AD, 1326AD to 1430AD. To make the red flag even more obvious, the oldest and the youngest test results came from the same lab... the one in Arizona which is considered the most experienced and most accurate of all of them! The Arizona lab was given two of the four samples. These were sub-samples taken from the ends of the main sample with the Zurich and Oxford labs getting one sample from between the two Arizona sub-samples.
1988 C-14 Test Sample map
The proportion of old Linen to new Cotton varies from 44/60 percent to 60/40 percent in the C14 samples and completely accounts for the anomalous ages (which went unremarked) of the various sub-samples reported by the three labs in the 1988 tests, with the younger reported dates coming from a subsample with a larger portion of newer material, while the older reported dates coming from a sample with a larger portion of older material. Harry Gove, the inventor of the Atomic Mass Spectrometry technique of Carbon dating used on the Shroud samples, when asked how old the original material would have to be if it were contaminated with 40% 16th Century material to give a date of 1260AD. He did some calculations and said "First Century, give or take 100 years." This was confirmed:
" Ronald Hatfield, a scientist at Beta Analytic, the world’s largest radiocarbon dating service, a merging of threads from AD 1500 into a 2,000 year old piece of linen would augment the C-14 content, such that a 60/40 ratio of new material to old, determined by mass, would result in a C-14 age of approximately AD 1210 (Beta Analytic Laboratories, 2000).
So, yes, I like the carbon date... but not the abysmal sampling done that broke the agreed protocols for the C14 testing and took the sample to be tested from the worst possible site on the Shroud.