Shroud like coloration of linen, conservation measures and perception of patterns onto the Shroud of Turin

Abstract

We present new experimental results on ultraviolet laser processing of linen fabrics that complete and update the previous studies at the ENEA Research Centre of Frascati seeking a coloration mechanism able to reproduce the microscopic complexity of the body images embedded onto the Shroud of Turin. The achievement of a Shroud-like coloration of linens by using vacuum ultraviolet light pulses allowed to recognize the main photochemical reactions possibly involved in the coloration process. The identification of these reactions offered hints for long-term conservation measures of the body images on the Shroud of Turin. Finally, we discuss how image processing of photographs of the Shroud may cause misleading effects, which led some researchers to perceive, e.g., inscriptions and a second face on the backside of the cloth, which are unlikely to be on the Shroud, confirming that there is a narrow boundary between image enhancement and manipulation.