It is clear, Fig. 4, that for a given set of pre-mordanting conditions,
Zr-salt (150 mmol/L), as well as post-dyeing conditions,
increasing the madder natural dye percent (from zero up to 12%)
is accompanied by a gradual increase in the K/S values of dyed
samples (from 0 up to 0.9) which could be ascribed to the greater
availability and accessibility of dye molecules onto and/or within
the vicinity of the pre-mordanted substrate thereby enhancing the
extent of dye absorption, and helping to bond the dye with the
modified substrate, i.e. higher extent of dye interaction/fixation,
and hence deeper color strength.
It is also evident (Fig. 5) that,