Characterisation and durability of contemporary unsized Xuan paper

Abstract

In China, Xuan paper has been the paper of choice as artwork support and for conservation, for several centuries. However, little is known about its material properties, especially given the many grades of sized and unsized Xuan paper. In addition, there is a lack of information on its degradation. In this research, a selection of contemporary unsized Xuan papers was investigated, representing diverse raw materials. Seven out of twelve contemporary unsized Xuan papers were determined to be approximately neutral and contain > 2% alkaline reserve, indicating good durability. Viscometry was used to determine the degree of polymerisation (DP) as none of the samples gave significant reactions to the phloroglucinol spot test. The average DP of ten contemporary unsized Xuan papers is ~ 1700, excluding two papers that have presumably been sun-bleached, and that exhibit significantly lower DP. Using X-ray fluorescence, it can be demonstrated that Ca and Si are the dominant elements and interestingly, Ca content is directly correlated with ash content and with alkaline reserve. Accelerated degradation was performed at two sets of environmental conditions, i.e. 90 °C, 30% RH and 60 °C, 70% RH, and the established degradation rates agreed with the Collections Demography model of paper degradation meaning that degradation of Xuan papers proceeds in the same way as other types of paper. This research gives fundamental insights into contemporary unsized Xuan papers, which exhibit good stability during accelerated degradation despite the low starting DP in the context of the samples used in this study. Our findings may inform methods of Xuan paper production, selection of Xuan paper for conservation purposes, as well as preventive conservation of Xuan paper-based artefacts.

The pursuit of further miniaturization of screen printed micro paper-based analytical devices utilizing controlled penetration towards optimized channel patterning

“…Further image processing was carried out in ImageJ software to determine the RGB values of the resultant color of each measurement. The obtained RGB values were transformed into grayscale intensity values through the weighted method, also called the luminosity method, in which each channel contribution is weighted according to its wavelength 35 . Moreover, to reduce any variations due to lighting conditions, RGB values from the background (zone of the pH strip that did not react with the sample) were transformed to grayscale intensity values in the same fashion, and then used to normalize the grayscale intensity values corresponding to each pH measurement.…”

“…Xuan paper is a traditional Chinese handmade paper usually used for Chinese calligraphy and painting, being the preferred paper for the conservation of paper-based artifacts. It is primarily composed of bark fibers of blue sandalwood (Pteroceltis tatarinowii), growing in calcium-rich soil, and rice straw (Oryza Sativa) growing in silica-rich soil 34 , 35 . Luo et al demonstrated that Xuan paper shows a similar temperature and light-induced degradation behavior as most western papers 36 .…”

Characterization of Korean handmade papers collected in a Hanji reference book

“…Different traditions and crafts explored various plant materials for papermaking through history both chronologically and geographically [1][2][3]. The variety of material and crafts process in East Asian countries makes papers that have different properties, such as Chinese Xuan paper [4,5], Japanese Washi [6,7] and Korean Hanji [8][9][10][11]. Among them, the Korean traditional handmade paper, commonly refers as Hanji, is a traditional symbol and heritage treasure from the Korean peninsula [10].…”

Deterioration of Contemporary Kaihua Handmade Paper: Evolution of Molecular, Supermolecular and Macroscopic Structures

“…Traditional handmade paper, as an important carrier of inheriting human civilization, is featured excellent performance of its durability (Hubbe and Bowden 2009; Jeong et al 2014a,b; Luo et al 2019). It enjoys a great reputation as the king of paper that could last for more than 1000 years (Luo et al 2021;Tang et al 2017). Kaihua paper is a kind of legendary handmade paper in China, which was used exclusively by the imperial palace in the Qing Dynasty.…”

“…Although modern papermaking techniques have enhanced the production e ciency, the resultant loss of quality in handmade paper, especially long-term stability, calls for a united effort on this common decline. (Luo et al 2021;Baty et al 2010). Hence, it is of fundamental importance to understand the dynamic degradation of paper in multi-scale structures, and nd out how an accumulation of microscopic variation of cellulose structure results in the macroscopic deterioration of handmade paper involving discoloration and loss of mechanical resistance, which will enable ultimately access to preparing long-life handmade paper and possessing the great signi cance to the restoration of ancient books and cultural relics.…”