In recent years, studies on the Holy Face have experienced substantial growth, although, up to date, no scientific study has been published in a referenced journal.
Art-historical studies have suggested a possible identification of the Face of Manoppello with the Veil of Veronica kept in the Basilica of St. Peter in Rome. But how far and how can you take this path of research? This study proposes to address this issue in the light of recent new studies carried out by the author on the original manuscript Opusculum de Sacrosancto Veronicae Shroud (Code H3) by Giacomo Grimaldi kept in the Vatican Secret Archives and repeatedly brought as a crucial document by supporters of that thesis. Further research has been effected on the frame of the Holy Face, dating back to the fourteenth century and now preserved in the Museo del Tesoro in San Pietro. The author, professional photographer, also proposes some photographic analysis on the relics.

The chemical nature of the image pigmentation, fundamental for hypotheses of the origin of images seen from both sides of the Veil of Manoppello, is discussed on the basis of spectral and micro-chemical analysis of natural byssal threads of the mussel Pinna nobilis. Two questions are considered: (i) what pigment gives the natural brown color of byssal threads and (ii) is it possible to chemically modify this pigment in order to obtain colors seen in the Veil.
Natural byssal threads under investigation have different tints of a brown color. This color is unaffected either by typical solvents, strong reducing agents or neutral hydrogen peroxide at room temperature. However, in alkaline media peroxide brighten the color. In particular, the procedure similar to proposed for the oxidative degradation of melanins [1] results in suspension of pale yellow particles, but if action of peroxide is stopped earlier, threads become yellow with fragments completely discolored and with some damaged areas seen under microscope.
The results obtained point to melanins as pigments responsible for the color of byssal threads, which is not unexpected because melanins are the most popular animal pigments accountable for the color of skin, hair, eyes and feathers. Ratio of two main forms of melanins: brown-black eumelanin to reddish-brown pheomelanin is different in human hair of different colors [2]. Both are macromolecular systems forming cross-linked oligomers from units derived from aminoacids tyrosine and cysteine. The exact structure of melanins is still under debate and the observed color depends strongly on the chemical composition, structure of oligomers and the dispersion of pigment granules. In general, colors of melanin range from black through brown and red to yellow (i.e., colors of the Veil) and color changes can be induced by strong oxidants or bleaching agents.
In conclusion, it looks highly probable that some degradation of natural byssus pigments, melanins, is responsible for different colors of images on the Veil of Manoppello. Thus, there is some similarity with the image on the Shroud of Turin created by a dehydrative oxidation of the cellulose of the linen.

References
[1] A. Napolitano, A. Pezzella, M.R. Vincensi, G. Prota: Tetrahedron 51, 5913-5920 (1995).
[2] C.R. Borges, J.C. Roberts, D.G. Wilkins, D.E. Rollins: Analytical Biochemistry 290, 116-125 (2001).

Outside of the context of the New Testament the word acheiropoietos was used for the first time in byzantine legends and greek historical writings with the meaning of an art object not made by human hands, often described as not painted, not made in a textile weaving, but by divine art, and put in comparison with the incarnation of the word of God in the womb of the Virgin Mary.
All eastern icons of the likeness of God have as her roots the likeness of Christ on a textile fabric, explained through legends, one of them - the case of the icon of King Abgar - as a miraculous impression of the face of Christ in a towel, and explained by another group of legends, of the so called image of Kamoulia or Kamouliana as the heavenly response on the desire of a woman who wanted to see Christ himself before get baptised.
I am convinced that only objects who are not understandable in so far one has the question of their fabrication could be the source of these legends. There were two objects with an image of Christ, one seemingly produced by impression of his face in a cloth, and one very fine and mysterious, so that nobody could give an explanation that goes farther than the real fact, that the image on the veil came directly from heaven.
Now, if we seek to representatives objects that correspond on all these conditions that we have described in very synthetic way, we can name for the first one the Shroud of Turin, and for the second one the veil of Manoppello. In other words: at the very ground and basic level of each legend or historical notice of an image of Christ done in a miraculous way, is to see an object like the Shroud or like the Veil of Manoppello.
That the same dependence is to be found even in the icons will be treated in the second part of my paper. All icons of the likeness of Christ, accepted in the eastern churches as true likeness are based on different readings and interpretations of an object as the Shroud and another thing like the veil of Manoppello. Perhaps the very roots of all these icons are the real still conservated relics in Turin and in Manoppello.
Which are the reasons for the admission of the two relics in order to be considered all two as acheiropoietos? With this question will deal the third part of the paper.

One aim of this research is to establish reasons why this Veil is so unique. I want to examine the message that it has for us. I have decided to concentrate on the semantic image. Semantics requires that we see the relationship between the language of words and the language of images. It would be impossible to read the message contained in the Shroud without the words contained in the Gospels. In the same way, it is impossible to find the meaning of the Veil without reference to the Gospels. In the case of the Veil, for a deeper understanding, it is necessary to analyse the structure of the material. All the more so, as the Veil allows us to enter into a field of exploration in a very unusual way and to start to find the secrets which have yet to be fully revealed.
I have been convinced that this is the way to gain knowledge of the Veil from the time when I was photographing it and had little expectation of being surprised. In a similar way to the Shroud, its meaning, which is hidden from the human eye, can be revealed with the aid of photography. I am a professional photographer and, when taking pictures of the Veil, I imagined I was producing a documentary file and nothing more. In the meantime, I analysed the pictures I had taken on a computer and reproduced them on a monitoring screen; there were marked differences in the photographs. The differences can be fully appreciated as the images were laid exactly in line with each other (the precision being outlined on the photos) and then the changes became apparent. The observations simply go unnoticed on casual inspection. These details are exposed when the Veil is examined under differing light conditions. The appearance of the changing images on the Veil impelled me to try to discover their true meaning.
The question has to be asked if these differences are not the capture of split-second moments in time that have been recorded on the Veil. Can we also put these recorded moments in a chronological order for a complete detailed version? I believe that it would be possible, with the aid of photography, to take a maximum number of photos and, after putting them into chronological order, to make an animated version of the whole scene.
From what I have observed, any critical mind can only want to seek an interpretation.