Thermochromicity in Wool Dyed with 6-Bromoindigo Depends on the Presence and Identity of a Solvent

Round 1

Reviewer 1 Report

The paper reports a very interesting study on the chemical physical behavior of wool dyed with IND, MBI and DBI in diverse experimental conditions. Particularly, interested results for wool dyed with MBI are discussed. The paper is well constructed, and several experimental data are reported and well considered.

My only doubt is about the presence in solution of indirubin isomers which may change the resulting colors and aggregates. Have the authors checked this possibility? Please, comment.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The article “Thermochromicity in Wool Dyed with 6-Bromoindigo Depends upon the Presence and Identity of a Solvent” describes the temperature and solvent dependence of dyeing with 6-Bromoindigo. The work is very interesting, but it is missing the bigger picture for heritage/conservation/heritage science overall. Here are some aspects to consider:

In the abstract its missing the importance of this work.

Scheme 1 caption should be below the figure

Could be helpful to have some of these color ranges exemplified in the introduction.

The general question is missing from the introduction. This leads to the reader not being able to follows the authors line of thought, i.e. “Why is this work important?”. This is only somewhat mentioned in the conclusion. Please also bring this to the introduction.

Figures 3, 4 and 5 captions should be below the figures

Why was there the choice of not doing HPLC? This is a technique which is still the most important when it comes to studying natural dyes.

Will you do ageing studies to understand how stable these colors are and if heating changes the color permanently as you said in the discussion? Permanently seems quite a strong term to use. If some ageing data exists, this may corroborate the use of this term. If not, maybe tone it down a bit.

Please also refer to other literature by Zvi koren, such as “New chemical insights into the ancient molluskan purple dyeing process”, where he provides new insights into the basic principles of chemistry associated with this craft.

Author Response

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Author Response File: Author Response.docx