natural dyes, logwood, indigo, Brazilwood, and aniline dyes

Ingredients

logwood, indigo, Brazilwood, aniline dyes

Evidence

"Conservators should consider to what extent it is necessary to preserve the original characteristics of the papers and inks, such as dyes or pigments in colored papers, ruling lines... e.g., natural dyes, logwood, indigo, Brazilwood, and aniline dyes."

Remarks

The study notes that aqueous treatments, particularly simmering water, often removed these sensitive organic colorants. Specifically, thin blue ruling lines present on most samples were removed by aqueous treatments (p. 141). Logwood, indigo, and Brazilwood are mentioned as potential colorants in the historical papers and inks (p. 144).