| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 176830 | Dyes and Pigments | 2012 | 11 Pages |
The major indigoids constituting modern and archaeological purple pigments produced from molluskan species include, in varying compositions, indigo, 6-bromoindigo, and 6,6′-dibromoindigo. Though woolen Tyrian Purple dyeings produced from these pigments were the most prized and precious of all dyeings in antiquity, a full chromatographic and colorimetric analysis of multi-fibered textiles dyed with these indigoids has not been previously performed. This current study reports on high-performance liquid chromatographic (HPLC) analyses conducted on the indigoid pigments and on woolen dyeings individually produced from them. In addition, comparative colorimetric analyses via reflectance spectrophotometry were performed on standard multifiber fabric swatches, each consisting of 13 different synthetic and natural fibrous materials. Each swatch was dyed with one of the cited indigoids. These colorimetric properties included the Kubelka-Munk spectral curves, color strengths at the wavelengths of maximum absorptions, color coordinates of the CIE L*a*b* and L*C*h* color spaces, and the color differences. Excellent functional correlations were observed among these properties and these relationships should be applicable to similar dyeings on other fabric materials. The results show that filament triacetate and nylon-66 possess the most remarkable color strengths of all the fiber materials investigated in all the dyeings, and of the natural fibers studied, wool possessed the highest color strength and cotton the poorest with all three dyes. Such chromatographic and colorimetric analyses would further our understanding of the colors produced from ancient, and modern, purple-dyed textiles.
► Multifiber fabric swatches dyed with indigo, monobromoindigo, and dibromoindigo. ► Chromatographic (HPLC) and colorimetric (CIE Lab) analyses of the pigments and dyes. ► Correlations among colorimetric properties for the blue, violet, and purple dyeings. ► Triacetate, nylon, wool, and acetate have highest color strengths in all dyeings. ► Better understanding of archaeological textiles dyed with molluskan purple pigments.
