Dye stability problems cost production time, waste material, and create customer complaints. Many common issues have clear, diagnosable causes — and straightforward fixes. This guide covers the problems we hear about most frequently and what to do about them.

Reactive Dye Issues (Cotton / Viscose)

This section covers issues with reactive dyes including the REACTOBOND range. See our reactive vs direct dye guide for substrate selection.

Problem: Poor Wash Fastness — Colour Bleeds on Washing

Common Causes: Insufficient alkali fixation, too-low temperature, short dyeing time, inadequate after-soaping, or using a direct dye where a reactive dye is needed.

Fix: Ensure correct Na₂CO₃ concentration (10–20 g/L), dyeing at 60°C for 45–60 minutes, followed by thorough hot soaping at 95°C to remove unfixed dye.

Problem: Unlevel Dyeing — Streaks or Patches

Common Causes: Too rapid salt or alkali addition, incorrect temperature profile, poor fabric preparation (sizing not fully removed), or machine issues causing uneven liquor circulation.

Fix: Add salt and alkali gradually in stages. Ensure fabric is thoroughly scoured and desized before dyeing. Maintain even liquor circulation throughout the dye cycle.

Problem: Shade Drift Between Batches

Common Causes: Variable water hardness, inconsistent dye weighing, temperature variation, or lot-to-lot dye strength variation from the supplier.

Fix: Use softened or demineralised water. Use calibrated scales for dye weighing. Request a TDS from your supplier for each dye lot and verify colour strength before use — Yobai Industries provides batch-specific TDS on request. See also our guide on dye compatibility and trichromatic systems.

Problem: Reactive Dye Hydrolysis — Low Colour Build-Up

Common Causes: Adding alkali before the dye has had sufficient time to exhaust onto the fibre, or storing dye solution for too long before use (hydrolysis in solution).

Fix: Allow the dye to exhaust with salt for 20–30 minutes before adding alkali. Always prepare fresh dye solution for each batch — do not store reactive dye solutions.

Acid Dye Issues (Wool / Leather / Nylon)

For full application guidance on acid dyes, see our acid dyes for leather guide.

Problem: Unlevel Dyeing on Wool or Nylon

Common Causes: Too rapid heating at the start of the dye cycle, incorrect pH, or using a dye with high substantivity that exhausts too fast.

Fix: Heat slowly (1–2°C per minute) from 40°C to the dyeing temperature. Use a levelling agent for difficult dyes. Start at pH 5–6 and drop slowly to pH 3–4 during the cycle.

Problem: Poor Rub Fastness on Leather

Common Causes: Insufficient fixation (pH not dropped low enough at end of dye cycle), excess dye on surface (over-dyeing), or inadequate fat-liquoring.

Fix: Drop the pH to 3.5–4.0 with formic acid in the final 20 minutes to fix remaining dye. Avoid over-dyeing — use minimum necessary dye concentration. Follow with proper fat-liquoring.

Problem: Shade Change After Drying

Common Causes: Some dyes undergo shade shift between wet and dry state. This is a known property of certain dye classes and should be accounted for in shade development.

Fix: Always evaluate shades in dry condition before approving. Match against the dry standard, not the wet shade. Some shade shift (up to 5–10%) is normal and must be built into the recipe.

Direct Dye Issues (Cotton / Paper)

Working with direct dyes? Compare them against reactive dyes in our reactive vs direct dyes guide.

Problem: Poor Wash Fastness

Common Causes: Direct dyes inherently have lower wash fastness than reactive dyes. No after-treatment applied.

Fix: Apply a cationic fixative after-treatment. This can improve wash fastness by 1–1.5 grades. For applications requiring wash fastness of 4–5, switch to reactive dyes.

Problem: Dye Precipitation in Bath

Common Causes: Too much salt added too fast, too-cold water used for dissolution, or water hardness causing the dye to precipitate.

Fix: Dissolve dye in hot water (70–80°C) before adding to the bath. Add salt gradually in stages. Use softened water if precipitation is a recurring problem.

Solvent Dye Issues (Plastics / Wood / Inks)

For grade selection guidance on solvent dyes, see our how to choose solvent dyes for plastics.

Problem: Colour Fading During Plastic Processing

Common Causes: Dye not thermally stable at the processing temperature of the polymer.

Fix: Check the heat stability rating of your dye against the processing temperature. Switch to a higher-stability grade — Solvent Yellow 146 or Solvent Orange 62 for engineering plastics processed above 200°C.

Problem: Poor Solubility in the Carrier Solvent

Common Causes: Wrong solvent type for the dye, or attempting to dissolve at too low a temperature.

Fix: Check the solubility data on the TDS for your specific dye. Warm the solvent slightly to improve dissolution. Request a TDS from Yobai Industries for compatibility data on your solvent system.

When to Contact Your Dye Supplier

Some stability problems are process-related (fixable by adjusting your procedure), but others can indicate a dye batch issue — inconsistent strength, contamination, or incorrect formulation. If you have ruled out process causes, contact your supplier with:

Yobai Industries quality guarantee: Every batch we ship is tested for colour strength and solubility in our in-house QC lab before dispatch. If a batch issue is confirmed, we replace or credit — no arguments. Contact us via WhatsApp (+91 97277 32326) for technical support on any dye purchased from us.