Imaging Diagnostics Coupled with Non-Invasive and Micro-Invasive Analyses for the Restoration of Ethnographic Artifacts from French Polynesia

Round 1

Reviewer 1 Report

Article entitled Imaging diagnostics coupled with non-invasive and micro-invasive analyses for the restoration of ethnographic artifacts from French Polynesia  is a very  interesting study about the modern scientific investigation of two rare ethnographic art objects. 

Comments for author File: Comments.pdf

Author Response

Reviewer #1

Article entitled Imaging diagnostics coupled with non-invasive and micro-invasive analyses for the restoration of ethnographic artifacts from French Polynesia (Authors: Claudia Colantonio, Luca Lanteri, Alessandro Ciccola, Ilaria Serafini, Paolo Postorino, Erminia Censorii, Doinita Rotari and Claudia Pelosi) is a very interesting study about the modern scientific investigation of two rare ethnographic art objects. Imaging diagnostics methods (multi- spectral imaging, 3D UV-induced fluorescence, SEM microscopy) have been coupled with integrated with analytical diagnostic tests (XRF, FTIR and SERS spectroscopy). The obtained results offer to the conservator very important information about the materials, the realization techniques and state of conservation. The originality of this study consists in the highlighting of the presence of rare organic natural materials used for producing of these artifacts (supports like tapa, cocos and feathers, adhesives like natural rubber, colorants like cochineal), for realization techniques (colorants like turmeric for preparation drawing) and the precious information about the degradation products and later interventions.

Authors reply: thank you so much for your positive evaluation of the paper and for having underlining the originality of the results.

I have two observations:

341 – missing the verb in the following phrase:  Comparison with several studies published in scientific literature, especially in the transverse section of the coconut fiber with its multi-cellular pattern (micro fibrils of  different sizes) with a polygonal shape and a thick wall, and a central lumen (Fig. 9d) was performed.

Authors reply: thank you for the observation. The sentence has been corrected and the verb added

360-361 – to be clarified the following phrase: The presence of iron can be ascribed to the use of red ocher (named 'ele in the local language of Polynesia), and also to the tannins of some of the barks of the most common species.   

Authors reply: thank you for the observation. The sentence has been modified to make it clearer. Iron, detected in the tapa, can be associated to natural earths and ochres (containing this element) added to the organic dye used to paint the surface of the artifact. But, iron can be also a constituent of the natural tannins that are contained in the bark used for obtaining the tapa base support.

This subject is very interesting for specialists in conservation and restoration art objects and after the above revisions, I strongly recommend the article for publication in Heritage journal.

Authors reply: thank you again for the very positive evaluation of the paper and for the recommendation to publish it in Heritage journal.

Reviewer 2 Report

The study by Colantonio used a wide range of analytical methods to characterize two Polynesian ethnographic artifacts. This study is outstanding in several regards: (1) the scientific methods are appropriate and well executed; (2) the writing shows clarity and accuracy; (3) Polynesian cultural objects have been little studied before, so it is important to collect related data to understand the raw materials involved; (4) The application of colloidal silver to obtain SERS data is well done.  I strongly recommend the publication of this high-quality study. I only have  a few minor comments:

1. I think the IR and Raman spectra are done very well. Could the authors provide tables in the supplementary information that list the major peaks and their tentative assignments? Detailed reporting of such data will be very useful for future researchers.
2. The abstract and conclusion sections are too general. The combination of multiple imaging and chemical analysis methods has become a standard practice in conservation science today. It is not really necessary to discuss the advantage of this analytical approach; it is self-evident. I think it would be better to discuss the specific findings of this study to help advance our understanding of Polynesian craftsmanship. Is any material discovery novel or unique? Would it be possible to discuss how Polynesian and European folk art used different materials to achieve similar results?  

Author Response

Rewiewer #2

The study by Colantonio used a wide range of analytical methods to characterize two Polynesian ethnographic artifacts. This study is outstanding in several regards: (1) the scientific methods are appropriate and well executed; (2) the writing shows clarity and accuracy; (3) Polynesian cultural objects have been little studied before, so it is important to collect related data to understand the raw materials involved; (4) The application of colloidal silver to obtain SERS data is well done.  I strongly recommend the publication of this high-quality study. I only have  a few minor comments:

Authors reply: thank you so much for your positive evaluation of the paper and for strongly recommending its publication in the Heritage journal.

1. I think the IR and Raman spectra are done very well. Could the authors provide tables in the supplementary information that list the major peaks and their tentative assignments? Detailed reporting of such data will be very useful for future researchers.

Authors reply: thank you for the suggestion. The tables were added in the Supplementary Materials as Table S2, Table S3 and Table S4. Table S2 concerns the sample of adhesive from tapa; the Table S3 the sample adhesive from headdress and Table S4 concerns the SERS assignments.

1. The abstract and conclusion sections are too general. The combination of multiple imaging and chemical analysis methods has become a standard practice in conservation science today. It is not really necessary to discuss the advantage of this analytical approach; it is self-evident. I think it would be better to discuss the specific findings of this study to help advance our understanding of Polynesian craftsmanship. Is any material discovery novel or unique? Would it be possible to discuss how Polynesian and European folk art used different materials to achieve similar results?

Authors reply: thank you for the suggestion. According to your valuable comments, the abstract and conclusion sections have been re-written.

The main relevant findings have been highlighted by considering that very few studies have been published on similar objects, so any result is very important to increase the knowledge of the ethnographic objects investigated in the paper and recently restored in the laboratories of our university, and now again exposed in the Museum of Congregation of the Sacred Hearts of Jesus and Mary (Rome).

Concerning the last question (Would it be possible to discuss how Polynesian and European folk art used different materials to achieve similar results?), obviously, it would be interesting to explore Polynesian craftsmanship’s technology and the social meaning of art in the South Pacific cultures compared to the European tradition, but we think it is a challenging study which should involve the expertise of demo-ethno-anthropologists, art historians specializing in ethnological art or European and native curator of South Pacific art collections. So, we think that such kind of study is out of our competence and out of the aim of the paper.

Thank you again for your positive evaluation.