This is a welcome application of polarised microscopy to the difficult topic of fibre identification. A group of characters is found to separate Malvaceae (NZ species) from Moraceae (Pacific species). Full details are given of methodology and reference material, and limitations of the research are acknowledged. The structure and writing of the paper are clear, and I just have a few minor suggestions (below). The results will be of wide interest given the widespread use of barkcloth throughout the tropics until the 19th century, and the abundance of barkcloth objects in museum collections.

I have three more significant suggestions:
1. Although discussion throughout is of NZ vs Pacific species, in fact it is comparison of two families. This could be made clearer. If relevant anatomical properties are discussed at family level (e.g. in relevant volumes of Anatomy of the Dicotyledons) it would be to discuss these and perhaps give an indication of how specific to each of the two families these characters are.

1. Discussion of whether these characteristics could support genus-level identification. The last paragraph of the paper leaves me unclear - might more research allow this? Or is it unlikely to help? What do the authors think having handled so much material?

2. I was surprised not to see application of the technique, even to modern tapa or other fibre artworks. If the authors have carried out a pilot study, even on just a couple of pieces of known identity, it would greatly strengthen the utility of this work.

Minor comments
At the first occurrence of full plant names (e.g. 1.13. Broussonetia papyrifera) please give the author name, in this case Broussonetia papyrifera (L.) L'Hér. ex Vent. Or add them to table 1 with a note in text that full botanical names are given there.

When a genus name might refer to more than one species, it should be followed by spp. [abbreviation for species plural), e.g. 3.15 Ficus spp.

3.20 '(for e.g. ' - awkward phrasing; see also 'for e.g' at 1.29

4.36 '(for an example' - looks like more than one example

11.17 It might be worth reminding readers here this is a family comparison, Malvaceae vs Moraceae, rather than truly geographical (Pacific vs NZ).

17.40 Here and elsewhere, herbaria specimens could be called herbarium specimens

A couple of works have appeared at the time of submission of the ms that could be cited:
Smith, Margaret J., A. Sheila Holmes-Smith, and Frances Lennard. "Development of non-destructive methodology using ATR-FTIR with PCA to differentiate between historical Pacific barkcloth." Journal of Cultural Heritage (2019). https://www.sciencedirect.com/science/article/abs/pii/S1296207418303522

Tamburini, Diego, et al. "Scientific characterisation of the dyes, pigments, fibres and wood used in the production of barkcloth from Pacific islands." Archaeological and Anthropological Sciences 11.7 (2019): 3121-3141.

Thank you for the changes made to the paper. It is great to see this substantial contribution ready for publication. I particularly appreciate the detailed account of methods which will be very useful as a manual for future researchers.

There are just a few minor points where I would suggest changes:
Abstract: In the last sentence you could be more specific about the results. E.g. 'can be used to differentiate fibres at the level of Moraceae and Malvaceae.... - would be great to include genus names too

Keywords - don't need to repeat words already in title e.g. tapa

p. 6 There is a word order problem and incorrect italicisation in the last sentence (To this end...)

p. 7 Incorrect italics in last sentence.

p. 8. "Any swelling of individual cells that may have occurred with this technique would be consistent within a species" - but this would not help with comparisons between species which you go on to discuss. Do you mean to say "consistent across all material studied", which I think might be arguable if they are all soaked in the same material (but not if of different age and different types of source...). Or change meaning to say "...consistent within a sample but does not guarantee that cells in different samples will respond equally" which I suspect is the truth but unknowable.

p. 12. "Overall it was possible to differentiate New Zealand plant species..." - this is confusing wording. Strongly encourage rewriting along the lines of "differentiate plant fibres from the New Zealnd Malvaceae species from the Pacfic Moraceae species...". The morphological separation is family level, not species level.

p. 14 "...it was difficult to differentiate among species..." here you mean genera, not species, as differentiation of genera was not possible (& implicit then that species cannot be separated).

p. 19. Could delete the word 'potentially' in the last sentence. Don't undersell your work!

References: capitalisation of several articles eg Buck 1924, Collings 1978 is not consistent with rest. Worth checking all.