A good reactive dye specification tells the supplier exactly what to make, how it will be tested and what counts as a failure. It names the product, ties strength and shade to a sealed standard with written tolerances, lists the tests and methods, and covers compliance, packing and documents.
Keep it short enough that a plant's lab will actually follow it. One or two pages is usually enough. Attach it to every purchase order and refer to it in the contract.
Identity and end use
- State the Colour Index name, such as C.I. Reactive Red 195, and the supplier's trade name.
- State the reactive system if it matters to your process, such as vinyl sulphone or bifunctional.
- State the physical form: powder, granule or liquid. See the difference between powder, granule and liquid dyes.
- State the fibre, the dyeing method, such as exhaust, pad-batch or continuous, and the typical depth of shade.
- For blended dyes, require the supplier to declare every Colour Index component.
Quality requirements
- Strength: a percentage against the sealed standard, with an allowed range and the method that decides, such as a lab dyeing.
- Shade: a colour difference limit, such as ΔE CMC(2:1), under named light sources, with a visual check. See shade matching tolerances.
- Moisture: a maximum percentage, measured by loss on drying.
- Insoluble matter: a maximum percentage.
- Solubility: a minimum value in grams per litre at a stated temperature.
- Fastness: minimum grades for washing, light, rubbing and perspiration on your fabric, using named ISO 105 or AATCC methods.
- Fixation or exhaustion: a minimum value under your dyeing method, if your mill tracks it.
Compliance, packing and documents
- Compliance: no banned amines above the limit in your market, conformance with the ZDHC MRSL or your customer's list, and periodic test reports from an accredited laboratory.
- Packing: net weight per pack, pack type, sealed moisture-proof liner, pallet type and stacking.
- Labelling: product name, lot number, manufacturing date, net weight and hazard labels on every pack.
- Shelf life: the minimum remaining shelf life on arrival and the storage conditions assumed.
- Documents: a COA for each lot with actual results, a current safety data sheet in your market's format, and a TDS.
- Retention: the supplier keeps a sealed sample from each lot for an agreed period.
How to use the specification
Agree the specification before the first order and get the supplier to sign it. Approve a pre-shipment sample from each lot against the standard, or have an agent do it in Gujarat. Ask for the COA results before loading, so problems are fixed before the goods leave.
Review the specification once a year, or whenever you change mill, fabric or customer. For what each test on the COA should show, read the tests that should be on a dye COA.
Next step
We help you turn your current dye into a written specification, find makers who can meet it and check every lot against it. To start, book a free sourcing review.