They appear in the Italian language daily L’Indro (the links include translation into English):
Google Translate says: A much exploited in past to attribute an ancient history in a relic that is lacking is to take the hypothetical events attributed to a relic different and apply them to that, or to argue that two relics are actually the same thing. There are some stories that concern ancient images acheropite, ie ‘not made by human hands’, fabrics on which it would miraculously imprinted the image of Christ. One of them is the Veronica, another is called Mandylion , ie ‘handkerchief’ or ‘towel’ of Edessa . The
legend on this handkerchief took its first steps in the V century as an appendix of another apocryphal legend and free of historical verisimilitude, already known in the previous century, which told of a correspondence exchanged between Jesus and King Abgar V of Edessa . In the text known as the ‘ Doctrine of Addai ‘it is said that King Abgar had sent his messenger to Jesus, who not only gave him a letter, but he also painted a portrait. Towards the middle of the sixth century, the legend was further modified and instead of the painted colors there was talk of a miraculous image : seeing the inability of the messenger in painting the portrait, Jesus would have washed his face and he wiped with a towel ; and on the fabric would miraculously imprinted the image of his face
Google Translate says: To which attributes the discovery of the icon hidden for centuries in a niche of the walls of Edessa and prodigiously duplicated. A ‘icon, then, on two different media: the original on a towel folded four times (‘ rhakos tetradiplon ‘) and the copy on tile (‘ Keramion ‘). It was believed that the copy was formed by contact with the original on Keramion place to protect that niche. An Icon that in both formats ‘achiropita’, ie not painted by the hand of man, even to distinguish it from the pagan idols, facts instead of human hands (‘deadly works facta’) as reaffirm the imperial laws. Since then it was kept in the cathedral rebuilt by Emperor Justinian made. In 639 Edessa falls under Islamic rule, which saves the icon from the havoc of the Byzantine iconoclasts. From then on it is called Mandylion….