The ferrous sulphate
heptahydrate mordant gave the highest
value of ΔE* because the shade of dyed
fabric changed from brown to gray on
the dyed fabric. The copper sulphate
pentahydrate gave a dark brown shade on dyed fabric. The aluminum potassium
sulphate gave a light brown shade on dyed
fabric similar to the shade of the dyed
fabric without mordant. The stannous
chloride gave a light brown shade to the
dyed fabric when using pre-mordanting
and post-mordating techniques, but it gave
a light yellow shade on dyed fabric when
using meta-mordaing technique. This
may be due to the less complex-forming
ability of the metal ions with the dye
molecules in this technique.