Unveiling the Use of Natural and Early Synthetic Dyes in Indonesian Historical Silk Textiles

Dye analysis is an important subject in historical textile research because it helps researchers understand the structural and chemical features of colorants and provides a solid base to determine the date, provenance, and trade of textile artifacts. This study is the first investigation of dyes used in historical silk of Indonesia using high-performance liquid chromatography coupled with a diode array detector and mass spectrometry (HPLC-DAD-MS). Three Indonesian silk textiles dating from the nineteenth (19th) and twentieth (20th) centuries are selected from the Southeast Asian textile collection of the China National Silk Museum. Dyes are extracted from the representative silk threads of these artifacts and subjected to chromatographic analysis. The characterization results indicated the use of a variety of natural dyes in the studied threads. In particular, madder dye (Rubia spp.), lac dye (Laccifer lacca Kerr.), and Morindone dye (Morinda citrifolia L.) were used for producing red shades, while green yarns were dyed by a combination of indigo and safflower (Carthamus tinctorius L.) yellow dyes. Furthermore, this study provides the first proposal of the use of saffron (Crocus sativus L.) dye in Indonesian textile dyeing during this period. In addition, Congo Red (C.I. 22,120), Orange I (C.I. 14,600), and Diamond Green B (C.I. 42,000) were identified, signifying the adoption of early synthetic dyes by Indonesian dyers. The current work takes advantage of the sensitivity and reliability of the HPLC-DAD-MS technique in dye analysis in order to give a report on the chemical aspects of coloring materials used in Southeast Asian textiles in the 19th and 20th centuries.