Onionskin has been used for dyeing since a long time ago. It is known that the coloring matter in onionskin is quercetin. In the present paper, we dyed wool fabrics with commercial quercetin and compared the results with those dyed with onionskin extraction. It was revealed that higher K/S values were observed at 380-400nm for the fabrics dyed with quercetin, and the K/S values decreased with increasing wavelength. The amount of adsorption onto wool fabrics increased with increasing quercetin concentration in the dye bath. In addition, a positive correlation was observed between K/S values at 410nm and the amount of adsorption of quercetin onto the fabrics. On the other hand, wool fabrics dyed with onionskin extraction showed higher K/S values at 380-400nm, as did the fabrics dyed with quercetin. It is noteworthy that higher K/S values at about 500nm and the higher values of a* in the CIEL* a*b* system were observed in onionskin dyeing, which means that the fabrics dyed with onionskin have a more reddish color than the fabrics dyed with commercial quercetin.
