3.3. Evaluation of color fastness
The dry and wet rubbing fastness, washing fastness, and light
fastness of the dyeing samples were measured. The CIELab values of
the dyed fabrics before and after washing test are shown in Table 8,
and dye fastness properties with respect to rubbing and light are
summarized in Table 9. There is no obvious improvement in fastness
properties in most cases. However, the washing fastness
decreased in samples subjected to premordanting with ferrous
chloride, and did not change in samples treated with stannous
chloride.
The rubbing fastness properties of the flax samples dyed under
optimized conditions without mordant and after premordanting
are indicated in Table 9. The rubbing fastness reached a grade of >4,
except in the cases for untreated fabric mordanted with ferrous
chloride, whose rating of wet rubbing fastness was 3e4 (slightly
below average). As seen in Table 9, the ratings for color fastness to
light in terms of the degree of color change and color staining were
good to very good