Plan a trial for your application
Cotton yarn exhaust dyeing
At the same yarn count and process conditions, compare shade depth, levelness and lot-to-lot color difference.
Washed denim appearance
Dye the same base fabric, run an identical washing cycle and compare hue before and after washing.
Purchase specifications and incoming inspection
Include the intended grade or current specification in the enquiry. Use the table to compare selection criteria and inspection conditions. The specification agreed by both parties defines the contractual limits. ENVO · Indigo Blue catalogue and specifications ↗
| Property | Unit | Published or agreed specification | Test conditions and checks |
|---|---|---|---|
| Dye content | % by mass | ENVO published powder grade ≥94.0 | Accept powder and granulated material separately. Specify method and dry or as-received basis. |
| Tinting strength | Relative % | Agree against a sealed reference sample held by both parties. | Use cotton yarn from the same lot and identical reduction conditions. |
| Color difference | ΔE | Agree against target swatches before and after washing. | Record instrument, light source, colour-difference formula and base fabric. |
When approving a sample, record the grade, methods, limits and specification revision. On receipt, match the packing lot number to the lot-specific COA and record the measured values and release decision.
Chemical identity
| Database entry | Molecular or composition formula | Molar mass |
|---|---|---|
| Indigo | C16H10N2O2 | 262.26 g/mol |
The values refer to the compound indicated. Confirm hydrate form, solution concentration and blend composition for the commercial grade.
From samples to commercial delivery
Packaging and receiving
Published packaging is 25 kg bags. Distinguish powder and granules by assay, net weight and lot on the contract.
Storage and handling
Seal retained samples after opening and link them to the colour standard. Check for dust or broken granules on receipt.
Sample and order lead times
Specify colour code, surface treatment or filler grade and whether a single lot is required. Confirm trial quantity, MOQ, retention across lots and arrival.
Questions from the plant
Why do shades differ at similar dye content?
On the same yarn under the same dyeing conditions, compare colour difference, dye uptake and lot-to-lot repeatability.
Why does the same product weight give a different depth of shade?
Correct for actual dye content and identify powder or granules. Run the samples in the same dyebath conditions.
Report a delivery or batch issue
Include the order number, lot number from the package, label photos and inspection records for the affected lot. When retesting, check Form supplied, active dye content, undertone and impurities.
Request documents for your application
TDS · Technical data sheet
For grade selection and sample approval, specify the grade and revision required.
SDS · Safety data sheet
Specify the country or region of use and the required language.
COA · Certificate of analysis
Request a sample COA during supplier review. For incoming inspection, provide the actual lot number.