Dyeing of Rajshahi silk with basic dyes: Effect of modification on dyeing properties

Abstract Colourfastness properties of degummed Rajshahi silk (Bombyx mori improved multi-voltine variety) were studied as a function of exposure to sunlight in air, washing with soap solution and spotting with acids and alkalis under different modifying and dyeing conditions. Study showed that 30% acetic acid and 20% tannic acid together was the best modifier for dyeing with Chrysoidine-Y, magenta, brilliant green, Victoria blue-β, Crystal violet and Auramine O basic dyes. Among the dyes, brilliant green exhibited best colourfastness under the prolonged exposure to sunlight in air. Washing with soap solution did not deteriorate colours at room temperature (27°C), but deterioration was observed with the increase of temperature. All the dyes used withstood their colours on silk to a great extent on washing with soap solution, although it slightly decreased with the increase of washing temperature. Spotting with acids and alkalis gave satisfactory results in most cases with the exception for sulphuric acid a...