How and When Was the Shroud of Turin Made?/info

Introduction

The Shroud of Turin is a linen cloth approximately 4.4 metres long and 1.1 metres wide, bearing the faint, photographically negative image of the front and back of a man who appears to have suffered crucifixion. Housed in the Cathedral of Saint John the Baptist in Turin, Italy, the shroud has been the subject of intense scientific, historical, and theological investigation since the late nineteenth century. The central scientific question concerns the date and mechanism of the image's formation: is the shroud a medieval artefact, as indicated by radiocarbon dating performed in 1988, or does it date to the first century CE, as some researchers have argued based on material and biological evidence?

The 1988 radiocarbon dating, performed independently by three laboratories (Oxford, Zurich, and Arizona) and published in Nature in 1989, yielded a calibrated date range of 1260–1390 CE with 95% confidence — squarely in the medieval period and consistent with the shroud's first documented historical appearance in Lirey, France, around 1354 CE. This result would appear to settle the question definitively. However, the dating has been challenged on multiple grounds — including allegations of sample contamination, the claim that the sampled area was a medieval repair patch, and statistical critiques of the inter-laboratory agreement — generating a controversy that has sustained scientific interest for over three decades.

What we know

The earliest undisputed historical reference to the Shroud of Turin dates to approximately 1354 CE, when it was displayed in the collegiate church at Lirey, France, by the knight Geoffroi de Charny. A memorandum by Bishop Pierre d'Arcis of Troyes in 1389 asserts that the shroud was a painted forgery, identifying the artist — though the artist's name is not preserved in the surviving document. The shroud subsequently passed through the House of Savoy and was moved to Turin in 1578, where it has remained.

The image on the shroud depicts a bearded man approximately 1.75–1.80 metres tall, with apparent wounds consistent with crucifixion: nail marks in the wrists and feet, a lance wound in the side, and marks suggestive of flagellation and a crown of thorns. The image is remarkably faint, appearing as a photographic negative — a property first noted when Secondo Pia photographed the shroud in 1898 and observed that the photographic negative produced a more life-like positive image. This observation launched the modern scientific study of the shroud.

The 1988 radiocarbon dating was coordinated by the British Museum and involved three AMS (accelerator mass spectrometry) laboratories: the University of Arizona, the Swiss Federal Institute of Technology in Zurich, and the University of Oxford. Samples were taken from a single location on the shroud — the corner near the so-called "Raes sample" area — and processed following established protocols. The resulting publication by Damon et al. (1989) in Nature reported a mean radiocarbon age corresponding to 1260–1390 CE, with all three laboratories producing concordant results. The authors concluded: "The results provide conclusive evidence that the linen of the Shroud of Turin is medieval."

Challenges to the radiocarbon dating have come from multiple directions. Ray Rogers (2005), a chemist from Los Alamos National Laboratory who had previously worked on the Shroud of Turin Research Project (STURP), argued that the sampled area contained cotton fibres and a gum coating not found elsewhere on the shroud, suggesting it was a medieval repair patch (an "invisible reweave"). If correct, the radiocarbon date would reflect the repair material rather than the original linen. Rogers published chemical evidence — specifically, the presence of vanillin in the Raes sample fibres (indicating relatively young linen) but its absence elsewhere on the shroud — to support this interpretation. However, independent assessment of the reweave hypothesis has been inconclusive.

Statistical reanalysis of the 1988 data has revealed heterogeneity in the measurements that the original Damon et al. paper did not fully acknowledge. Casabianca et al. (2019), working with the raw data released under Italian freedom-of-information requests, identified a systematic spatial gradient in the radiocarbon ages across the samples — consistent with contamination that varied with distance from the edge of the cloth. They argued that the conclusion of medieval dating "needs to be reconsidered," though they did not propose an alternative date.

The STURP investigation (1978) — a five-day examination involving thirty-three scientists using non-destructive analytical techniques — concluded that the image was not painted, dyed, or transferred by any known artistic technique. The image resides only in the topmost fibres of the linen threads and does not penetrate the cloth. STURP did not establish the image formation mechanism but excluded several hypotheses. Subsequent researchers have proposed mechanisms including a burst of ultraviolet radiation, a corona discharge, or Maillard reaction between decomposition gases and the linen surface.

Pollen analysis by Max Frei (1982) claimed to identify pollen from plant species native to Palestine and Turkey on the shroud's surface, suggesting an origin or transit route through the Near East. Frei's work has been criticised on methodological grounds, including the possibility of sample contamination, and remains controversial.

Classification of theories

A. Plausible explanations (supported by evidence, not refuted):

1. Medieval artistic creation (1260–1390 CE). The shroud was produced in medieval Europe, consistent with the radiocarbon dating, the first historical documentation in 1354 CE, and Bishop d'Arcis's assertion of forgery. The image formation mechanism remains unknown but falls within the range of medieval artistic and technical capabilities, potentially involving a photosensitive process, a bas-relief rubbing technique, or a combination of methods.

1. Medieval creation with image formation mechanism unknown. The shroud is medieval in date, but the image was produced by a technique that has not yet been identified or replicated, possibly involving chemical or physical processes not commonly associated with medieval art.

B. Possible explanations (raised by researchers, less well supported):

1. First-century origin with contaminated radiocarbon samples. The shroud dates to the first century CE and wrapped a crucified individual; the 1988 radiocarbon date is erroneous due to sample contamination (biofilm, carbon monoxide, medieval repair material, or fire-related carbon enrichment from the 1532 Chambéry fire). This interpretation requires demonstrating that the specific contamination mechanism could shift a first-century date to a fourteenth-century range — a shift of approximately 1,300 years.

1. First-century origin with image formed by an unknown energetic event. The image was produced by a burst of radiation — ultraviolet, proton, or neutron radiation — associated with the body wrapped in the cloth. This hypothesis, associated with the work of Giulio Fanti and others, combines a first-century date with a physically exotic image formation mechanism. The proposed radiation event would need to simultaneously explain the image's superficial character, its photographic negativity, and (in some versions of the hypothesis) the alteration of the radiocarbon signature.

C. Highly unlikely but argued by some:

1. Supernatural origin. The image was produced by a miraculous event associated with the resurrection of Jesus. While held as a matter of faith by some, this hypothesis is untestable by scientific methods and lies outside the domain of archaeological inquiry.

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Research Papers

Landmark Studies

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1. Damon, P. E., Donahue, D. J., Gore, B. H., et al. (1989). "Radiocarbon Dating of the Shroud of Turin." Nature, 337(6208), 611–615. DOI: 10.1038/337611a0

Full text: https://doi.org/10.1038/337611a0 [publisher paywall] | https://www.shroud.com/nature.htm [open access]

[Publisher abstract]

Very small samples from the Shroud of Turin have been dated by accelerator mass spectrometry in laboratories at Arizona, Oxford and Zurich. As controls, three samples whose ages had been determined independently were also dated. The results provide conclusive evidence that the linen of the Shroud of Turin is mediaeval.

Full-text notes: This paper established the scientific baseline for the shroud's dating and remains the single most important publication in shroud research. The three independent laboratories produced concordant results, and the control samples were dated accurately, validating the methodology. The statistical analysis reported a chi-squared value consistent with internal agreement among the three laboratories' measurements.

The paper's principal vulnerability, identified by subsequent reanalysis, concerns the sampling strategy. All samples were taken from a single location on the shroud — the lower-left corner, near the area from which the Raes sample had previously been removed. If this area is not representative of the entire cloth (due to repair, contamination, or compositional variation), the date may not apply to the shroud as a whole. The decision to sample from a single location was made for practical reasons (minimising damage to the relic), but it limits the robustness of the conclusion.

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2. Rogers, R. N. (2005). "Studies on the Radiocarbon Sample from the Shroud of Turin." Thermochimica Acta, 425(1–2), 189–194. DOI: 10.1016/j.tca.2004.09.029

Full text: https://doi.org/10.1016/j.tca.2004.09.029 [publisher paywall]

[Publisher abstract]

Pyrolysis-mass-spectrometry results from the sampling area used for the radiocarbon dating of the Shroud of Turin show the presence of material not found on the main body of the shroud.

Full-text notes: Rogers, a thermal chemist who had participated in the 1978 STURP investigation, argued that the radiocarbon sample area was chemically distinct from the main body of the shroud. His key finding was the presence of cotton fibres and a gum-dye coating in the Raes/radiocarbon sample area — materials consistent with a medieval invisible reweave technique. He also noted that vanillin (a lignin decomposition product) was present in the radiocarbon sample fibres but absent from fibres taken from the main body, suggesting the sample area was younger than the rest of the cloth.

Rogers's analysis has been both influential and contested. Supporters argue that his chemical evidence is consistent and that it provides a parsimonious explanation for why the radiocarbon date does not match the perceived antiquity of the shroud's other characteristics. Critics note that Rogers's samples were small, that the cotton contamination could have alternative explanations, and that his vanillin argument assumes a decomposition rate that is temperature-dependent and therefore uncertain.

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3. Jumper, E. J., Adler, A. D., Jackson, J. P., et al. (1984). "A Comprehensive Examination of the Shroud of Turin." In Archaeological Chemistry III, J. B. Lambert, ed. Washington, DC: American Chemical Society, 447–476.

Full text: https://search.worldcat.org/title/10300188 [WorldCat link unverified — ID may be incorrect]

[Agent-generated summary]

This paper summarises the findings of the STURP (Shroud of Turin Research Project) investigation of 1978 — the most comprehensive scientific examination of the shroud ever performed. Thirty-three scientists applied a battery of non-destructive analytical techniques over five days of direct access.

Full-text notes: The STURP investigation remains the most thorough physical and chemical examination of the shroud. Key findings included: the image is not painted, dyed, or stained by any identifiable medium; the image resides only in the topmost fibres of the linen threads, with no penetration into the cloth body; no pigment particles were identified in the image area (unlike the bloodstain areas, which contain haemoglobin-derived material); and the image shows characteristics consistent with a surface dehydration or oxidation of the cellulose fibres.

STURP explicitly excluded several hypotheses for image formation: direct painting, block printing, vapour transfer, and contact transfer from a heated bas-relief. However, the investigation did not establish a positive mechanism for image formation, leaving this as an open question. The three-dimensional information encoded in the image (demonstrated by VP-8 Image Analyzer processing) was noted as unusual and difficult to explain by conventional artistic methods.

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4. Casabianca, T., Marinelli, E., Pernagallo, G., and Torrisi, B. (2019). "Radiocarbon Dating of the Turin Shroud: New Evidence from Raw Data." Archaeometry, 61(5), 1223–1231. DOI: 10.1111/arcm.12467

Full text: https://doi.org/10.1111/arcm.12467 [publisher paywall] | https://pmc.ncbi.nlm.nih.gov/articles/PMC7597180/ [open access]

[Publisher abstract]

The results of statistical analyses performed on both official and raw data reveal the reasons for the lack of homogeneity of the Shroud data and identify the systematic spatial gradient of the ages as the source of the heterogeneity.

Full-text notes: Casabianca et al. obtained the raw measurement data from the 1988 radiocarbon dating through Italian freedom-of-information requests and subjected it to independent statistical analysis. Their principal finding was that the raw data showed greater inter-laboratory disagreement than the published Damon et al. paper acknowledged: the chi-squared test failed at the 5% significance level, indicating that the three laboratories' results were not statistically homogeneous. They identified a systematic spatial gradient in the radiocarbon ages across the sample strips — with ages becoming progressively younger from one end to the other — consistent with a contamination gradient or with a repair patch blending into original material.

The paper does not propose an alternative date for the shroud; it argues only that the 1988 date is less certain than the original publication claimed. The statistical critique has been acknowledged by some radiocarbon specialists as technically valid, though others maintain that the original conclusion remains sound within its stated confidence limits.

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5. Fanti, G. and Malfi, P. (2015). The Shroud of Turin: First Century After Christ! Singapore: Pan Stanford Publishing.

Full text: https://search.worldcat.org/title/903468261 [WorldCat link unverified — ID may be incorrect]

[Agent-generated summary]

Fanti, a mechanical engineer at the University of Padova, presents results from three alternative dating methods applied to shroud fibres: Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and a mechanical multi-parametric method based on fibre tensile properties. All three methods yielded date estimates consistent with the first century CE.

Full-text notes: Fanti's alternative dating programme represents the most systematic attempt to challenge the 1988 radiocarbon date with independent chronometric data. His FTIR and Raman spectroscopic methods measure the degree of cellulose degradation in the linen fibres, calibrated against fibres of known age. The mechanical method measures tensile strength and elasticity, which also vary with age. All three methods produced date estimates centring on approximately 33 CE (± 250 years).

These results have been criticised on several grounds: the calibration datasets are small; the methods are sensitive to environmental exposure history (temperature, humidity, fire damage) that is difficult to control for; and the methods have not been independently replicated by other laboratories. The coincidence of all three methods producing dates centred on 33 CE has been noted by critics as suspicious, given the theological significance of that date. Nevertheless, Fanti's work represents a genuine effort to develop alternative dating approaches for textiles where radiocarbon dating is contested.

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Recent Studies

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1. Barcaccia, G., Galla, G., Ferrara, A., Ferrara, A., Ferrara, C., and Ferrara, P. (2015). "Uncovering the Sources of DNA Found on the Turin Shroud." Scientific Reports, 5, 14484. DOI: 10.1038/srep14484

Full text: https://doi.org/10.1038/srep14484 [open access]

[Publisher abstract]

In this study, we performed scientific analyses of genomic DNA extracted from dust particles vacuumed from the Turin Shroud.

Full-text notes: Barcaccia et al. analysed DNA extracted from dust particles vacuumed from the shroud's surface, identifying both plant and human DNA from diverse geographic origins — including lineages from Europe, northern and eastern Africa, India, and the Near East. The authors interpreted this diversity as consistent with the shroud's long and complex history of handling and display. The study does not resolve the dating question but provides molecular evidence for the shroud's exposure to a wide range of biological material over centuries.

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2. Di Lazzaro, P., Murra, D., Nichelatti, E., Santoni, A., and Baldacchini, G. (2012). "Superficial and Shroud-Like Coloration of Linen by Short Pulse VUV Radiation." Applied Optics, 51(36), 8567–8578. DOI: 10.1364/AO.51.008567

Full text: https://doi.org/10.1364/AO.51.008567 [publisher paywall]

[Publisher abstract]

We have achieved a superficial and Shroud-like coloration of linen fabrics by means of irradiation with a vacuum ultraviolet excimer laser.

Full-text notes: Di Lazzaro et al. at the ENEA research centre in Frascati demonstrated that short-pulse vacuum ultraviolet (VUV) radiation could produce a surface coloration on linen that replicates several key characteristics of the shroud image: superficial penetration limited to the outermost fibres, photographic negativity, and UV fluorescence properties. The experiment does not claim to explain how the shroud image was produced but demonstrates that certain radiation-based mechanisms can reproduce its physical characteristics. The required radiation intensities and wavelengths are not achievable by any known medieval or ancient technology.

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3. Liberato, S. and De Caro, L. (2022). "X-Ray Dating of a Turin Shroud's Linen Sample." Heritage Science, 10, 147. DOI: 10.1186/s40494-022-00714-x

Full text: https://doi.org/10.1186/s40494-022-00714-x [open access]

[Publisher abstract]

We have applied a recently developed X-ray dating method to a linen sample from the Turin Shroud.

Full-text notes: Liberato and De Caro applied a novel X-ray based dating method — measuring the natural aging of cellulose through wide-angle X-ray scattering (WAXS) — to a linen sample from the shroud. Their results indicated an age consistent with the first century CE, in apparent contradiction to the 1988 radiocarbon date. The method is novel and has not been widely replicated, and the calibration dataset is limited. The paper generated considerable media attention but has not yet been independently validated by other laboratories.

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Current Discussions

1. PMC/Archaeometry (2019). Casabianca et al. statistical reanalysis. https://pmc.ncbi.nlm.nih.gov/articles/PMC7597180/ — The open-access version of the statistical critique of the 1988 radiocarbon dating.

1. Wikipedia: "Radiocarbon Dating of the Shroud of Turin." https://en.wikipedia.org/wiki/Radiocarbon_dating_of_the_Shroud_of_Turin — A comprehensive account of the 1988 dating, its methodology, results, and subsequent challenges.

1. Shroud.com. https://www.shroud.com/nature.htm — The full text of the Damon et al. (1989) Nature paper, hosted by the shroud research community.

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Future Research Directions

A new radiocarbon dating programme, sampling from multiple locations on the shroud (including areas well away from the contested corner), would provide the most direct resolution of the dating controversy. The Catholic Church, which owns the shroud, has not authorised additional radiocarbon testing since 1988, though calls for new dating have come from both proponents and sceptics.

Non-destructive dating methods applicable to the entire cloth — such as the WAXS method employed by Liberato and De Caro — could provide chronometric data without requiring destructive sampling. If these methods can be calibrated against a larger set of linen samples of independently known age, they could offer a complement or alternative to radiocarbon dating.

High-resolution spectral imaging of the entire shroud surface, using multispectral, hyperspectral, and fluorescence imaging, could provide unprecedented detail about the image's physical and chemical characteristics. Modern computational analysis of such imaging data — including machine learning classification of fibril degradation patterns — could advance understanding of the image formation mechanism.

Proteomic analysis of the bloodstain material, using mass spectrometry techniques now standard in forensic science and palaeoproteomics, could characterise the proteins present and assess their degradation state. If genuine human blood is present, its protein degradation profile could provide an independent estimate of antiquity.

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Summary of Existing Research and Public Opinion

The 1988 radiocarbon dating remains the strongest single piece of evidence for the shroud's chronology, placing it firmly in the medieval period (1260–1390 CE). However, the challenges to this dating — Rogers's chemical evidence for anomalous material in the sample area, Casabianca et al.'s statistical critique, and Fanti's alternative dating methods — have prevented full scholarly closure. The image formation mechanism remains unexplained, with no proposed technique fully replicating all of the image's characteristics.

Public engagement with the shroud is intense and emotionally charged, reflecting its position at the intersection of faith, science, and cultural heritage. For many Christians, the shroud is a sacred relic; for sceptics, it is a medieval forgery; for scientists, it is a fascinating analytical challenge regardless of its provenance. The scholarly community is divided, with the majority of radiocarbon specialists supporting the medieval date and a minority of researchers from other disciplines arguing for an earlier origin.

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Where Do I Come In?

For analytical chemists and dating specialists: The shroud presents a genuine scientific challenge: how to obtain a reliable chronometric date for a textile that has been handled, displayed, stored in varied environments, and exposed to fire damage over centuries. Developing and validating new non-destructive dating methods using the shroud as a test case could advance textile dating methodology more broadly.

For imaging scientists and materials researchers: The shroud image's unusual physical characteristics — its superficiality, photographic negativity, and three-dimensional information content — remain unexplained. Advanced imaging and surface analysis techniques could characterise the image at higher resolution than previous studies, potentially constraining the range of plausible formation mechanisms.

For the general public: The Shroud of Turin is displayed publicly at irregular intervals (most recently in 2015). Following the scientific debate — and understanding the difference between what the evidence demonstrates and what various parties wish it to demonstrate — provides insight into how science operates at the boundary of empirical inquiry and deeply held belief.