Evaluating Five Consolidants for Black-Dyed Māori Textile Artefacts

This article reports testing of the efficacy of five consolidants (sodium alginate, zinc alginate, Paraloid (R) B-72, TRI-Funori (TM), Methocel (R) 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 (R) A4C (TM) in H2O and TRI-Funori (TM) 0.5% w/v in H2O were recommended for further exploration for use on deteriorated paru-dyed muka.