New Insight on Medieval Painting in Sicily: The Virgin Hodegetria Panel in Monreale Cathedral (Palermo, Italy)

Round 1

Reviewer 1 Report

The presented manuscript deals with a multi-analytical characterization of a medieval painting. In general, the paper is well written, results are properly explained and discussed, conclusion well addressed. There are some points that need to be reviewed. Therefore, I suggest minor revision.

Minor remarks:

X-ray radiography (X-Ray): replace the acronym with XRR.

Digital microscopy (DM): replace the acronym with OM.

Fourier Transform Infrared Spectroscopy: the acronym is not necessary, more than a set-up is used.

Concerning FTIR and Raman attributions, I suggest using symbols to indicate the normal modes. There is a discontinuity in the attribution of the absorptions. Sometime the attribution is labeled with the symbol, sometimes with the extended word. Sometimes only the wavenumbers are reported.

e.g., Page 7, lines 268-269, 290; Pag 9, lines 345-349; Page 12, lines 399, Page 12, lines 401-406

Page 7, line 293: the OH bending refers to the two absorptions not to water of hydration. Moreover, how do you justify the simultaneous presence of gypsum and anhydrite?

Pag 9, line 344-45: … ESEM/EDX suggesting the use of red dyestuff stabilized by tin oxides. This is an interesting point. How do you support your hypothesis? Is there any literature on this?

Page 12, lines 440-441: The sentence, in the present form, is just a little bit cryptic, please rephrase it.

Figure

The labels in figure 2 are very small and the overall quality is poor. Please provide a figure with a better quality/resolution

The elemental maps in figures 3 and 4 are small and poor in resolution. Please improve.

Author Response

Responses to comments and suggestions from Reviewer 1

The presented manuscript deals with a multi-analytical characterization of a medieval painting. In general, the paper is well written, results are properly explained and discussed, conclusion well addressed. There are some points that need to be reviewed. Therefore, I suggest minor revision.

Minor remarks: 

Reviewer 1: X-ray radiography (X-Ray): replace the acronym with XRR.

Authors: OK, we replaced the acronym as the reviewer suggested.

Reviewer 1: Digital microscopy (DM): replace the acronym with OM.

Authors: OK, but if the reviewer agrees, we should use DOM (digital optical microscope)

Reviewer 1: Fourier Transform Infrared Spectroscopy: the acronym is not necessary, more than a set-up is used.

Authors: Ok, we erase the acronym.

Reviewer 1: Concerning FTIR and Raman attributions, I suggest using symbols to indicate the normal modes. There is a discontinuity in the attribution of the absorptions. Sometime the attribution is labeled with the symbol, sometimes with the extended word. Sometimes only the wavenumbers are reported. 

e.g., Page 7, lines 268-269, 290; Pag 9, lines 345-349; Page 12, lines 399, Page 12, lines 401-406

Authors: Based on the comments and suggestions from the reviewer, we have changed the original manuscript. All the absorption attributions are reported as wavelength in cm^-1.

In order to clarify or to point out when required we also specified vibrational mode using symbols.

Reviewer 1: Page 7, line 293: the OH bending refers to the two absorptions not to water of hydration.

Authors: Thank you for your comment. We apologize, but as you mentioned the weak peaks at 1681 and 1624 cm−1 are due to traces of calcium sulphate dihydrate.

Reviewer 1: Moreover, how do you justify the simultaneous presence of gypsum and anhydrite?

Authors: According to scholars, the presence of both gypsum and anhydrite sometimes is attested in different layers but in the same painting. The simultaneous presence of both Ca-sulphate minerals is due to the production process such as the incomplete burning of the raw gypsum and we added the reference.

Reviewer 1: Pag 9, line 344-45: … ESEM/EDX suggesting the use of red dyestuff stabilized by tin oxides. This is an interesting point. How do you support your hypothesis? Is there any literature on this?

Authors: Yes, this type of red dye was available between the end of the 18th century and the beginning of the 19th century as attested by Kirby et al: (Kirby, J.; Spring, M.; Higgitt, C. The technology of red lake pigment manufacture: study of the dyestuff substrate. Natl. Gallery Tech. Bull. 2005, 6,71-87.)

Reviewer 1: Page 12, lines 440-441: The sentence, in the present form, is just a little bit cryptic, please rephrase it.

Authors: Thank you for your suggestion, we rephrased this sentence.

Reviewer 1: Figure

The labels in figure 2 are very small and the overall quality is poor. Please provide a figure with a better quality/resolution

Authors: Ok, we changed figure 2 and you can see the .tif file.

Reviewer 1: The elemental maps in figures 3 and 4 are small and poor in resolution. Please improve.

Authors: Ok, we improved figures 3 and 4 and you can see the .tif files.

Reviewer 2 Report

The manuscript its clear, relevant and well-structured, but it also has some errors that the authors must improve. The references that they used are relevant, but they must to add more references to justify some affirmations that they made and to support the scientific soundness of the article.

-       Please, review the bibliography at the end. There are references that are not good cited such:

27. Daveri, A. et al.

28. Salvadó, N. et al.

You must to add all the names of the authors.

-       In the References, please, add the DOI of the publications.

-       Please, add the chemical formula of the pigments and other compounds that you identify.

-       Unify the way that you wrote Virgin Hodegetria. Sometimes you used italics, and other times you used “”.

Line 24: cinnabar/vermilion, please, can you specify? In other times you only put vermilion.

Lines 47-48: Please, put Santa Maria Nuova in italics.

Line 55: Please, add a reference to support this affirmation after “(around 1183)”.

Line 56: Add reference after “(about 1200)”.

Line 64: Add some more references to support this.  

Line 73: Please, add a reference after “cross”.

Line 75: Please, add a reference after “masses”.

Line 83-87: Add some more references to support this.

Line 92: Renaissance writers such as… add some examples and references.

Line 268: is it possible to hypothesize about the possible sources of calcium sulphate with silicate impurities such as Celestine?

Line 319: Please, use italics for “sottomodello”.

Line 331: Can you explain the use of Cu and Hg in the gilding areas?

Line 334: Can you explain the presence of S in clayey pigments?

Lines 340-341: Can you specify the type of oxalates and sulphates that you found? Please, add references that you used for the identification of the compounds.

Line 346: Please, add references that you used for the identification of the compounds.

Line 363: Is it possible to determine if it is cinnabar or vermilion in a justified way?

Line 388: Please, can you explain the identification of Ba-sulphate?

Line 419: Please, add a reference after “retouches”.

Line 441: Please, add references after “light” to support this.

Line 444: Please, add references that you used for the identification of the compounds.

Lines 454-459: Please, add some examples and references.

Line 476: Please, add a reference after “else” to support this affirmation.

Line 482: Put 2 with subscript.

Line 489: Please, add examples and references after 14^th centuries.

Line 498: Please, add some references.

Line 505: Please, add some references.

Author Response

Responses to comments and suggestions from Reviewer 2

Comments and Suggestions for Authors

The manuscript its clear, relevant and well-structured, but it also has some errors that the authors must improve. The references that they used are relevant, but they must to add more references to justify some affirmations that they made and to support the scientific soundness of the article.

Reviewer 2: Please, review the bibliography at the end. There are references that are not good cited such:

27. Daveri, A. et al.
28. Salvadó, N. et al.

You must to add all the names of the authors.

Authors: You are right, we completed the references.

Reviewer 2:  In the References, please, add the DOI of the publications.

Authors: Ok we added the DOi of the publications.

Reviewer 2:   Please, add the chemical formula of the pigments and other compounds that you identify.

Authors: Ok, we added the chemical formula as you suggested.

Reviewer 2:       Unify the way that you wrote Virgin Hodegetria. Sometimes you used italics, and other times you used “”.

Authors: Thank you for your suggestion. We changed and we used italics.

Reviewer 2:  Line 24: cinnabar/vermilion, please, can you specify? In other times you only put vermilion.

Authors: Thank you for this comment. As in our case Hg-based pigment was used in a restoration intervention we didn’t ascertain if it was natural or synthetic pigment. In our results and discussion, we mentioned it as mercury-based red as in the literature [Gliozzo 2021]. In the previous studies, the authors used cinnabar and we reported it with the corresponding reference.

Reviewer 2:  Lines 47-48: Please, put Santa Maria Nuova in italics.

Authors: Yes, we did.

Reviewer 2:  Line 55: Please, add a reference to support this affirmation after “(around 1183)”.

Authors: Ok we added the reference

Reviewer 2:  Line 56: Add reference after “(about 1200)”.

Authors: Ok we added the reference

Reviewer 2:  Line 64: Add some more references to support this.  

Authors:  Ok, we added this reference

Reviewer 2:  Line 73: Please, add a reference after “cross”.

Authors: Ok, we added the reference

Reviewer 2:  Line 75: Please, add a reference after “masses”.

Authors: Ok, we added the reference

Reviewer 2: Line 83-87: Add some more references to support this.

Authors:  Ok, we added the reference

Reviewer 2: Line 92: Renaissance writers such as… add some examples and references.

Authors: Ok, we added the references:

Reviewer 2: Line 268: is it possible to hypothesize about the possible sources of calcium sulphate with silicate impurities such as Celestine?

Authors: As celestite is associated with gypsum deposits in sedimentary rocks [we added a reference: Gomez 1998] there are different quarries in Southcentral Sicily, central Greece, Creta islands and Cyprus. So, it is not easy to know the possible sources.

Reviewer 2: Line 319: Please, use italics for “sottomodello”.

Authors: Ok we used italics

Reviewer 2: Line 331: Can you explain the use of Cu and Hg in the gilding areas?

Authors: Thank you for your suggestion, we better explained this sentence in the manuscript.

Reviewer 2: Line 334: Can you explain the presence of S in clayey pigments?

Authors: S and Ca are related to the underlying ground layer; we better explained this sentence and we added some references for Cl presence.

Reviewer 2: Lines 340-341: Can you specify the type of oxalates and sulphates that you found? Please, add references that you used for the identification of the compounds.

Authors: Thank you for your comment, we checked the spectra and we better specified.

Reviewer 2: Line 363: Is it possible to determine if it is cinnabar or vermilion in a justified way?

Authors: Yes, it is possible [Gliozzo 2021] but as we mentioned above, Hg-based pigment was used in a restoration intervention we didn’t ascertain if it was natural or synthetic pigment.

Reviewer 2: Line 388: Please, can you explain the identification of Ba-sulphate?

Authors: Probably, barium sulphate was used mixed with some pigments during the last restoration intervention. We added the reference.

Reviewer 2: Line 419: Please, add a reference after “retouches”.

Authors: Ok, we added the reference

Reviewer 2: Line 441: Please, add references after “light” to support this.

Authors: Ok, we added the reference

Reviewer 2: Line 444: Please, add references that you used for the identification of the compounds.

Authors: Ok, we added the references

Reviewer 2: Lines 454-459: Please, add some examples and references.

Authors: Thank you for your comment. We changed the sentences and we better specified the use of Abies sp. wood.

Reviewer 2: Line 476: Please, add a reference after “else” to support this affirmation.

Authors: Ok, we added the reference

Reviewer 2: Line 482: Put 2 with subscript.

Authors: Thank you for your suggestion, we did.

Reviewer 2: Line 489: Please, add examples and references after 14^th centuries.

Authors: Ok we added the reference

Reviewer 2: Line 498: Please, add some references.

Authors: Usually in the conclusion reference are not mentioned but as requested we added the reference.

Reviewer 2: Line 505: Please, add some references.

Authors: Usually in the conclusion reference are not mentioned as requested we added the reference.