Dried cumin seeds were purchased from the local market.
Formic acid, sulphuric acid (H2SO4), Glauber salt were supplied by
S D Fine Chemicals Ltd., Mumbai, India. Silk fabric was purchased
from Piyush Syndicate, Mumbai. Rota dyer machine from Rossari
Lab Tech., Computer Colour Matching System (Spectra Scan 5100+,
Data colour International, Lawrenceville, NJ, USA) and TECHCOMP
UV-visible spectrophotometer (UV-VIS 8500) were used for
testing.