An Assessment of the Deterioration of Fabricated Metal Thread with Light, and Temperature and Humidity Factors: A Focused Study of Asian Textile Collections at the Metropolitan Museum of Art, New York

Abstract

To investigate the deterioration of textiles with metal thread, I surveyed 40 textile objects, dating from the 11th to the 19th century from Korea, China, Japan, and Central Asia at the Metropolitan Museum of Art, New York. This survey included various types, widths, and thicknesses of metal thread. In addition, deterioration was examined under the microscope and color information was collected using the spectrophotometer. While investigating metal thread in the collections, I fabricated 12 different types of metal samples with metal leaf(24K gold, silver, and copper leaf), adhesive (hide animal glue and a mixture of hide animal glue and iron oxide red), and paper substrate(Korean mulberry and Taiwanese kozo paper). The accelerated deterioration process of those fabricated samples was carried out using a light box(UV and daylight), and a humidity cabinet. In the light experiment with blue scales textile fading card(aka, blue wool standard), the metal leaf began to peel off during the deterioration process with 756,000 lux-hours UV and daylight. In the temperature and humidity experiment, I could observe the reddish tarnish on copper, and some part of it began to peel off. Color reading on the light exposed samples showed that the degree of color change on the surface follows the amount of exposure as it increased over time. On the other hand, color change on the samples after artificial deterioration using temperature and humidity factors showed random change of color with occasional spikes. Distortion of original shape worsened in the samples exposed to temperature and humidity.

Cleaning Fabricated Metal Thread: A Post‐treatment Stability Assessment after Artificial Deterioration and the Application of Synthetic Soil

“…On the naturally-soiled textiles, the colors and particle sizes of soil materials were diverse due to the different circumstances of their original environmental factors and archaeological textiles with metal thread (Park et al, 2018).…”

“…The deterioration process of the metal thread described in environmental deterioration used with light(UV and daylight), and temperature and humidity, was followed by previously published research (Park et al, 2018). The light deterioration lux-hours; and daily average temperature and humidity inside the light box were 30.58℃ and 34.06% respectively.…”

“…The deterioration in a controlled environment had insufficient soiling/staining on the surface of samples for cleaning stability assessment, quite unlike historic and archaeological conditions to which textiles with metal thread would be subjected (Park et al, 2018). In order to mimic these condition, to the surface of the metal thread samples we added synthetic soil mixture consisted of:…”

Insight Into the Crystallinity of Chinese Ancient Silk by Synchrotron Radiation-Based and Conventional X-ray Diffraction Methods

“…In order to better understand the degradation process, evaluate the ageing status, and provide suggestions for the effective preservation of historic or archaeological silk, artificial ageing was often employed to stimulate the ageing process. Artificial ageing was achieved in a controlled environment with ultra violet(UV) radiation, soil embedding, volatile organic compounds(VOC), inorganic gas, animal flesh, or elevated temperature and humidity (Kang, 2009;Baek et al, 2012;Kim et al, 2012;Kim et al, 2013;Kim et al, 2014;Oh et al, 2014;Kim et al, 2016;Park et al, 2018;Park et al, 2019). Among these factors, dry-heat accelerated ageing was adopted in this study, based on the mechanism of ageing starting from a single fiber and then spreading to the whole fabric.…”