Review Reports

Round 1

Reviewer 1 Report

The article presents very interesting and important results of colourant analyses of textiles excavated at the ancient Phrygian site of Gordion in Turkey. The textiles constitute one of the largest and most significant corpora of Iron Age textiles from western Asia. Whilst information about textile dyeing in the ancient Near East has been researched for decades on the basis of written sources, the direct evidence is extremely limited due to poor textile preservation in the region. The results of presented in this article are therefore of great significance for our understanding of dyeing materials and techniques not only in Phrygia but also more widely.

The article is well written but certain aspect could be better clarified for both specialist and non-specialist readers.

 

Methods

One of the aspects that would be useful to understand at the outset is the choice of analytical techniques and the reasons behind them.

In the discussion section on mordants it is stated that “permission for destructive testing might be sought” (line 524) – if the fact that analyses had to be non-destructive determined the choice this should be stated at the outset. Yet, the use of HPLC for 2003-Tx-2F “in order to determine whether there was any protein fiber” (193) presupposes destructive sampling. The “Self-sampling powder” (line 149) should also be explained in more detailed, particularly the issues that might arise from using such material.

The choice of HPLC for proteinaceous fibre identification seems somewhat baffling, especially since proteomic methods are currently available, particularly at the Smithsonian. At the same time, why was HPLC not used for dye analysis in this case considering that unlike DART-MS it allows also quantitative not only qualitative analysis?

The choice of various methods should be clearly explained.

 

Materials

Although textile structural analysis and fibre identification were carried out before colourant analysis (Ballard et al. 2010), it might be useful for the authors to summarise briefly these data for the benefit of the readers, as they are of direct relevance to colourant analysis. At present, textile description is rather haphazard. E.g. line 490: “2003-Tx-10. This consists of several seemingly identical layers of fine plain weave fabric stuck together” – why is the weave described here but not in other cases? Furthermore, most images show lumps consisting of multiple layers and multiple textiles (as is also apparent from the numbering of textiles but is not explained), further necessitating careful consideration of each analysed object. It is also important to understand the rationale behind the sampling/selection of material.

Each analysed object/textile should be described in the Materials section (the simplest way would be in a table) following standard textile analytical procedures (weave, thread count, thread structure/twist/diameter etc.) and providing contextual information (location within burial etc.).

There is no discussion of the fibre nature although it is clear from Fig. 23 for example that the textile is made using plant fibre. The fact that experimental goethite coating was tried on linen suggests that the archaeological textiles were identified as linen as well. Fibre nature is fundamental in any discussion of dyeing since proteinaceous and cellulosic fibres have very different affinities for dyes. These data should also be included in the table summarising the material analysed and considered in the discussion.

 

Specific comments

371-372 “With over two millennia of leachate and microbiological decay, the presence of a highly pure goethite entity reflecting a prior life as a textile is extraordinary.” – rephrase – goethite was not a textile but a textile colourant.

 

373 “goethite weaving” – goethite was not woven, goethite-coated thread was (cf. “goethite-coated polyester” in line 379).

 

Fig. 21 – the details of textile microstructure and colour in this and most other images are invisible and the images are therefore useless – micrographs with proper lighting and scale are needed.

 

383 “yardage” – what is mean by this term?

384 “soft hand” -  “soft handle”?

 

395-396 “When examined under a low-powered microscope, the golden strands were found to have been dabbed with indigo before the yarns were plied” – how exactly did you determine that they were “dabbed” and what does that mean in terms of dye application technique?

 

423 “semi-dyed indigo state” – what does “semi-dyed” mean?

 

428-429 “The ingenuity and frugality used to produce a more uniform dyeing is seen in the presence of its being dabbed on one of the two singles of a two Z plied yarn” – again, please explain how does one identify ‘dabbing’.

 

436-438 “This presence of multiple forms of indigo on the samples from 2003-Tx-3 Front (Figures 24-25), on 2003-TX4 (Figures 26-27), on 2003-Tx-6 (Figures 28-29), and the back of 2003-Tx-9 (Figure 30) may have contributed to the shades of maroon, purple, or brown.” – do you mean in combination with madder?

 

442 “the distinctive contrast between the front and back of fragment 2003-Tx-2” – this could be due to preservation/taphonomy or the fact that layers are of different textiles on front and back – these possibilities are not discussed.

 

356 “madder fragments” – “madder-dyed” fragments

 

456-461 The present hues do not reflect the original colours – the discussion of difference in dyeing techniques based on the present colour of the fragments is an over-interpretation.

 

464-465 “Avoiding these components, the dye produced a brown shade, even with the presence of indigo, alum, iron, and perhaps copper—the latter three as mordants” – the later discussion on mordants states that their identification is not possible without further research and the quantities Al, Fe and Cu in the samples discussed as reported in table 3 is lower or not above all the other samples.

 

544 “The use of alum as a mordant further indicates the chemical expertise of the Phrygian colorists.” – Alum was not discussed until this point and the above section on mordants clearly indicates that further research is needed to identify mordants.

 

576-577 “We hope that this paper will serve as incentive for such research and spur an interest in colorants, dyeing techniques, mordants, and early alum refining in the Near East” - interest in this topic has long existed among the linguists and there is a plethora of publications on the subject, which the author should at least mention.

 

 

Author Response

Your detailed and thorough notes were a tremendous help. We have attempted to clarify and explain the topic more specifically. Proteomics for 2003-Tx-2Front was not operative at MCI during the early phase of our research; now that it is, we are trying to re-schedule a proteomics analysis. Thank you for your encouragement to do this!

Author Response File: Author Response.pdf

Reviewer 2 Report

Review of the Manuscript

“Ancient Chromophores and Auxiliaries: Phrygian Colorants from Tumulus MM at Gordion, Turkey, ca 740 BCE”

The subject of the manuscript fully corresponds to the goals of the special issue. Materials and methods are described in great detail, starting with how the materials were obtained, up to the timing of the research itself. There is a clear division into inorganic and organic categories.

An interdisciplinary approach is very successfully applied. The analysis of the chemical characteristics of dyes fits well into the historical context, namely information about the textiles from Tumulus MM (the tomb of Phrygian king, the 8^th century BC). It is great that the authors take into account the broad context. For example, they understand that “The burnt level of the City Mound has provided context for the Tumulus MM textiles, both in terms of surviving fragments of cloth and also loom weights and other tools indicating large-scale textile production” (Lines 104–106). Particularly, this allowed them to state that “the textiles from Tumulus MM and the remains from the City Mound provide evidence for wide-scale textile manufacture and use at Gordion, which 116 yielded fabric in a variety of weaves, some with geometric patterning, and in subtle and 117 vivid hues achieved by ingenious dye chemistry” (Lines 115–118).

The overall merit of the manuscript is very positive. However, I would like to clarify, is it really necessary to repeat twice that the Tumulus MM is the largest at Gordion? Compare the following two statements:

(1) “Tumulus MM, called “MM” for “Midas Mound,” is the largest burial mound at the site, now preserved to a height of 53 meters” (Lines 42–44)

and (2) “Tumulus MM is the largest of approximately 120 tumuli at Gordion” (Line 69).

Also, the word “Title” seems to be superfluous in the title of the article (Line 3).

Comments for author File: Comments.pdf

Author Response

Thank you for your sympathetic review of our manuscript. We have tried to correct our errors! Please see the attached!

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors

The paper reports the collected data on few remains coming from the Tumulus MM, specifically the possible colorants (either in terms of dyes and inorganic pigments/mordant) are discussed referring to relevant previous studies.

The collected data are discussed in a proper and well organized way taking into consideration the difficulties to deal with such old and delicate samples. Degradation processes and additional materials related to the excavations cannot be excluded and the authors discussed the results in a correct way. I do believe that the paper is worth to be published despite the presence of few typos within the text that are highlighted in green in the uploaded documents.

 

In my personal opinion it will be useful to add a Supplementary section where the authors should give more details in relation to how they analysed the samples with the different instruments. Many references are correctly added to support the experimentation but more details would be appreciated to the convenience of future readers.

 

Here are my remarks:

Page 8 Figure 10, 11 and 12 are either called Table and mentioned in the text. This is confusing, there are table and should be reported as table and correctly numbered

 

Page 9 line 243 please add more details related to the type of known samples used for identification. More details are also needed regarding the modifies ablation system.

Why did you need to change the ablation system? did you have any problems related to S/N ratio or spurial signals? did you need to correct the data? did you use an internal standard?

I would like to suggest to add these details in a separated Supplementary materials for helping future applications

 

Page 9 line 250-254 This part is quite confuse. Honestly it is not clear your starting point. As a matter of fact, it is known that SEM-EDS is a qualitative technique. Nevertheless, some people do make personal comments on quantities when ratio among elements is quite evident. The confrontation among element is always difficult as their intensity sometimes is not only related to their amount but also to matrix effects, samples efficiency, etc.

Just speak of semi quantitative pointing out the limits of it.

But please avoid saying significant quantity, fair quantity, low quantity as it is quite confusing.

 

Page 10 Figure 14 and 13 need to be improved. Axes are in some cases missing or difficult to read

 

Page 10 I would like to suggest to report the collected FTIR in a supplementary section. As here the confrontation and the discussion is quite important. As few are the spectra relevant to colorant identification, in particular in the case of archaeological and most specific textile samples,

 

Page 11 please uniform the line spacing to the previous text

 

Page 18 line 508-512 the citation would be more evident if you use CURSIVE font. Remove the paper number at the end

additional remarks are added in the enclosed PDF

Comments for author File: Comments.pdf

Author Response

Thank you very much for all your ideas and comments. We cannot add supplements to work that was completed several years ago but attached please find the article on the ICP-MS ablation--I think the system was too warm and the bromine standards evaporated. She needed to use a cooler method. Ms Dussubieux is now at the Field Museum in Chicago, if you have further questions. Or let me know and I shall ask her for you! I hope I have corrected Figures 13 and 14 properly. Thank you again for your all help.

Author Response File: Author Response.pdf