Eco-friendly printing of natural fabrics using natural dyes from alkanet and rhubarb

In the present work, the suitability of printing natural fabrics (wool, silk, cotton and flax) with two natural dyes (alkanet and rhubarb) using pigment-printing technique has been investigated. The effect of different factors, i.e. dye concentration, nature of thickening agent, type of fixation, concentration and type of mordant, has been studied. The printed goods were evaluated by measuring the K/S value and the overall fastness properties. Results show that the highest K/S value was obtained by using Meypro gum as a thickener. The K/S increases rapidly as the concentration of the natural dye powder in the printing paste increases from 10 to 40 g/kg printing paste. Moreover, results show that the printed goods, which were fixed via steaming, have relatively higher colour strength than their corresponding samples fixed via thermofixation. The effect of mordants on colour development was also studied and alkanet dye was chosen as an example for this investigation. The best results were obtained by using mordant at a concentration of 20 g/kg printing paste. Different colour yields could be obtained by using different mordants, and all of colour fastness results were ranging between very well and excellent.