Morphometric and experimental evidence for a cranial bandage hypothesis in the Sudarium of Oviedo

The Sudarium of Oviedo is a historical textile preserved in Oviedo, bearing blood stains and linear traces of uncertain origin. This study evaluates whether these features can be explained by the action of a cranial bandage applied during early post-mortem handling, within the broader context of ancient funerary wrapping practices in which cranial bandaging served stabilisation and containment functions. A three-stage analytical framework was developed. First, high-resolution raster scans were processed through a reproducible image-analysis pipeline including background correction, adaptive contrast enhancement, edge-preserving smoothing, percentile-based intensity mapping, and sub-pixel isoline extraction. These procedures enabled the identification of linear structures and local concentrations of intensity consistent with blood accumulation under external compression. Second, controlled laboratory experiments were carried out using a cranial model, linen textiles, and a warm blood simulant so as to replicate the sequence of postural changes and wrapping configurations derived from documented ancient funerary wrapping protocols. The image-based analysis revealed directionally coherent linear corridors across the frontal and occipital regions, with preserved orthogonality of the textile weave beneath the traces. Percentile isolines showed persistent clusters of high intensity that spatially correlate with anatomical prominences where compression would be expected. Experimental replication generated comparable linear flows, reorientation of fronts during positional changes, and compact accumulation points under light bandage pressure. Together, morphometric evidence and experimental outcomes indicate that the observed patterns are consistent with, but do not uniquely demonstrate, a compression-related wrapping mechanism. The framework provides a replicable method for evaluating compression-related traces in ancient textiles and informs broader archaeological interpretations.