Natural Dyeing Studies and Determination of Color Fastness with Isatis tinctoria L. (Brassicaceae) Species

This study evaluates.the dyeing performance and light fastness properties of natural dyes obtained from different parts of the Isatis tinctoria (indigo) plant on wool yarns. In today's environment, where interest in natural dyes is resurfacing due to increasing environmental concerns and the potential toxic effects of synthetic dyes, this study aims to contribute to the potential of natural dyes in sustainable textile applications. The findings show that although natural dyes are environmentally friendly and biodegradable, they have some limitations in terms of color variety and fastness properties. The fact that the indigo plant has historically been an important source of indigo and its wide distribution area supports its evaluation as an alternative natural dye source. The dyeing and light fastness analyses carried out within this scope reveal the applicability of indigo in the coloring of woolen textiles and contribute to scientific studies on the development of natural dyes. This study aims to comparatively evaluate the light fastness properties of root, flower, and fruit-derived natural dyes under mordant-free and mordant conditions. The findings showed that all mordant-free dyeings exhibited moderate light fastness (3), and that the fastness values increased with mordant application. In particular, a higher fastness value (4) was obtained in mordant dyeing with fruit extract. The results reveal that mordant plays a role in reducing photodegradation by strengthening dye-fiber interactions and that phytochemical differences depending on plant parts affect dye performance. However, the fact that the overall fastness levels remained at a moderate level indicates the need for further studies to improve the performance of natural dyes in textile applications.