Repair Of Ancient Literature Dyeing With Paper Studies

In order to obtain the similar color with a paper artifact being restored, the matching paper for restoration should be dyed, which is a common procedure in restoration of ancient texts. Traditional Chinese pigments and vegetable dyes are two main colorants frequently-used. From the surveys, we learned about that the traditional Chinese pigments used are gamboge, ochre, ink and so on, and the vegetable dyes are acorn cup, tea, sophora flower bud and gardenia. These colorants may cause potential hazardous effects on durability of papers, and the color stability also needs to be studied. In this paper, the durability and color stability of dyed papers are researched by accelerating experiments. By a series of comparison, the right colorants to dye restoring papers and the dyeing process would be determined.The conclusions are as follows:1. Stability of dyed papers and the mechanism Papers dyed by Marie’s pappy traditional Chinese pigments in soft tubes have a poor durability, so it cannot dye matching papers for restoration. The biggest culprits of the deterioration are phenol, an antiseptic existing in pigments, which has a strong corrosivity, can accelerate deterioration of papers and has an influence on preservation of papers for long time. The blocky traditional Chinese pigments do not cause much impact on durability of papers. There is iron ion in ochre, which would accelerate oxidation of cellulose. For this reason, it should be used carefully and fewer or unused. Natural vegetable dyes are a group of preferable colorants and do not damage the durability of papers. However, some of the vegetable dyes have poor color stability such as black tea, gardenia and sophora flower bud, which limited their uses in dyeing papers. Dye liquor of acorn cup is stable in color. The color difference of Xuan paper dyed by acorn cup is just2.77after sixty days’aging. Consequently, the dyed paper by acorn cup can be popularized since the good stabilities.2. Process improvement of dyeing paper(1) Gelatin can fix colors by increasing the bonds between dye and cellulose, giving papers properties of resisting permeation and diffusion of liquid. The effect is especially notable in vegetable dyes. Certain gelatin won’t do harm to the durability of papers but can reduce color changes of dyeing papers (light yellow colored paper, acorn cup colored paper) during dry-heat accelerated ageing.(2) The solutions of vegetable dyes are acidic. The experiment results of adjusting pH values of dye liquor are as follows. Following with the increased pH values of colorants, the color of the dyeing papers have slight change. The maximum color changes are below or approximately equal to three for papers dyed by acorn cup, black tea and sophora flower bud, while for gardenia is four, which are all in the phases of just noticeable values and would not affect the appearance of paper. By diluted with water, the dyes being adjusted pH will be light in color and close to the color of dyes not adjusted. The pH values of papers dyed by dyes adjusted pH are higher in varying degrees than papers dyed by dyes not adjusted pH values. In addition, the papers dyed by colorants overcome acid still maintain the preferable durability and color stability as undyed papers do. Therefore, adjusting pH values to neutral or alkalescent should be done before dyeing papers for restoration, so that can eliminate the hidden trouble of acid to durability of papers.