Using single-dye curves to investigate shade variation along a reactive-dyed fabric

Why can shade differences increase after washing when initial depth matches?

Final depth can be similar despite different exhaustion histories and amounts of unfixed dye. A mixed shade alone cannot identify which component caused the difference.

Separate the blend into individual dye exhaustion curves

Run single-dye and blend trials in parallel. Observe bath and fabric at corresponding times and retain swatches before and after soaping. Judge color under one illuminant alongside the changes in the bath.

Why does a mixed shade drift from the start to the end of a run?

Check uptake curves for each dye and changes in bath conditions. Trial the individual dyes in parallel. Cotton yarn exhaust dyeing: At equal yarn count and liquor ratio, compare dye uptake curves, levelness and shade depth after washing. Color matching with dye blends: With the target trichromatic combination, compare hue drift during heating and fixation.

Checking Relative tinting strength and Color difference

Relative tinting strength (%): Specify fibre, reference sample, shade depth and colour measurement method. Color difference (ΔE): Agree the illuminant, measurement geometry and calculation formula. Wet fastness (Grade): Specify the fabric used to assess staining and the wash conditions for the end-use test.

What to record

• Dye components
• Sampling point in time
• Bath conditions
• Color difference before and after soaping
• Light source

Technical references

• Jacquard Procion MX: reactive dye range ↗

Products and processes