Evaluating Five Consolidants for Black-Dyed Māori Textile Artefacts

ABSTRACT

This article reports testing of the efficacy of five consolidants (sodium alginate, zinc alginate, Paraloid® B-72, TRI-Funori™, Methocel® A4C) used by conservators for consolidation. The consolidants were tested for potential use on deteriorated black-dyed plant fibres, specifically paru-dyed muka (iron-tannate dyed fibre from harakeke; New Zealand flax, Phormium tenax), building on previous experimental work. Paru-dyed test fibres were pre-aged (light, with UV) to simulate museum artefacts, and then consolidated, after which their colour stability, strength retention, and acidity were measured. Consolidated test fibres were then artificially light-aged (UV-filtered) to test the stability of the consolidants over time (10 MLux hours; UV-filtered light), with colour stability, strength retention, and acidity re-measured after this ageing stage. A full factorial experimental design with four factors was used for testing: dye type, consolidant type, consolidant concentration, and accelerated light-ageing. Data were analysed using generalised linear models (GLM) coupled with analysis of variance (ANOVA) and simple effects procedures to test for interactions between factors and determine significant differences. Overall, this study found that using criteria of pH, strength, colour stability, and visual properties, that 0.5% w/v Methocel® A4C™ in H₂O and TRI-Funori™ 0.5% w/v in H₂O were recommended for further exploration for use on deteriorated paru-dyed muka.

KEYWORDS:

• Māori textiles
• consolidants
• iron-tannate dye
• tensile-testing
• Phormium tenax
• pH
• accelerated light-ageing
• methyl cellulose
• funori

Acknowledgements

Māori ownership and traditional knowledge of the plants, dyes, and artefacts investigated under Article II of The Treaty of Waitangi are acknowledged by the authors. The authors would also like to thank Kahu Te Kanawa for assistance with fibre preparation. Our research partners were Te Papa Tongarewa National Museum of New Zealand and Tamaki Paenga Hira Auckland War Memorial Museum.

Disclosure statement

No potential conflict of interest was reported by the author(s).

List of suppliers

Consolidants

Sodium alginate, Sigma-Aldrich New Zealand, PO Box 106-406 Auckland 1030, New Zealand

Zinc Acetate AR (Product no. 54901), ECP (Environmental Control Products), PO Box 34125, Birkenhead, Auckland 0746, New Zealand

TRI-Funori™ (starch derived from seaweed species Gloiopeltis furcate and Gloiopeltis tenax), TRI-Funori.com, 26 Barrett Street, Port Hope, Ontario, Canada L1A 1M7

Paraloid® B-72 (beads), Conservation Supplies, PO Box 8760, Havelock North 4157, New Zealand

Methyl Cellulose A4C, Talas, 330 Morgan Ave, Brooklyn, NY 11211 USA

Blue Wool Standards, INDX, PO Box 938 Christchurch, New Zealand

Grey Scale standard, INDX, PO Box 938 Christchurch, New Zealand

Elsec 765C Environmental Monitor, Littlemore Scientific Engineering: Dorset, UK.

Instron 4464 Universal Testing Machine, Instron Corporation: Canton, Massachusetts, USA

iButton Hygrochron Temperature/Humidity Logger with 8KB Data-Log Memory. 1-Wire interface and software. Maxim Integrated 160 Rio Robles San Jose, CA 95134 USA

Microelectrodes Inc. Micro pH Electrode - Model MI-4152, 40 Harvey Road, Bedford, New Hampsphire 03110, USA

Microsol Light Fastness Tester Model 495 (modified to operate with fan cooling, by Centre for Materials Science and Technology, University of Otago), James H. Heal and Co. Ltd.: Halifax, UK

Mylar® film (Product no. FLM04: 125 micron), Conservation Supplies, PO Box 8760, Havelock North 4157, New Zealand

Orion pH/mV/temperature meter - Model Star A2110, Thermo Scientific Water Analysis Instruments, 22 Alpha Rd Road, Chelmsford, MA 01824 USA

Tru Vue ®Conservation Reflection Control, UV Filter Glass, Tru Vue Inc., 9400 W. 55th Street, McCook, Illinois 60525, USA

Additional information

Funding

This work was supported by Strategic Initiatives Grant, Division of Sciences, University of Otago, New Zealand; C.L. Gregory Fund, Auckland Museum, New Zealand; Lottery, World War II Heritage and Environment Grant, Department of Internal Affairs, New Zealand .