natural organic dyes and lakes (Indian lac)

Ingredients

Indian lac, gum Arabic

Preparation Steps

Original Recipe Text

The study references traditional recipes found in several historical treatises including 'Resāleh dar Bayān-e Kāḡaḏ Morakkab va Ḥall-e Alvān' (p. 68). For the experimental paint samples (p. 71), the binder was prepared by treating two grams of solid gum Arabic with 25 ml of water in a beaker, heated gently for one hour with stirring every 10 minutes until a smooth gel was obtained. Dyes extracted from plant sources were allowed to evaporate in an oven at 40 °C until a thick fluid was obtained, which was then mixed with the gum Arabic binder and applied to paper using a brush (p. 71).

Evidence

"HPLC-MS as a micro destructive analytical technique for the characterization of natural dyes and lakes (Indian lac) used in some of the selected Shāhnāma manuscripts. In the present project, a few samples from Shāhnāma manuscript RAS 239 (UCL) and Shāhnāma manuscripts Persian 9 and Persian 933 (JRL) were analysed by the HPLC-MS technique."

Remarks

Organic dyes in Persian manuscripts are often difficult to identify due to low concentration and the presence of binders (p. 57). SERS was specifically applied to enhance the Raman signal which is often obscured by high backgrounds caused by fluorescence in natural dyes like madder, cochineal, and lac (p. 62). The investigated spectral range for the FORS detector was 250–900 nm with a resolution of 2.4 nm (p. 55).