Descrizione principale (Inglese)

This article examines the extraction and application of dyeing substances from Rubia tinctorum (dyer’s madder) on different textile fibers in the context of sustainable natural dyeing. The aim is to investigate how key factors—solvent type, extraction temperature and duration, state of the dye material, dye-to-fiber ratio, as well as the use of tannin additives and metal salts (FeSO₄, CuSO₄)—influence the final color and its fastness. A total of 50 experiments were conducted, combining different conditions of extraction and dyeing. The results confirm known dependencies, such as the higher absorption in protein fibers and the predictable effects of metal salts, while at the same time revealing discrepancies with commonly cited recommendations—for example, stable colors obtained despite high-temperature extraction, or the limited enhancement of red hues after the addition of calcium compounds. Attention is given to repeated extraction and dyeing, which demonstrate the stepwise release of different dye compounds, as well as to the comparison between R. tinctorum and R. cordifolia. The study highlights the importance of a systematic experimental approach, applicable even in non-laboratory settings, as a contribution to the advancement of sustainable practices in textile dyeing. Keywords: natural dyes, Rubia tinctorum, extraction, dyeing, anthraquinone dyes, textiles, experiment