MANUFACTURING / JAPAN SOURCING
Fabric lab dips and bulk approval: keep colour and hand separate
An approved small colour swatch is a reference for the next stage. Before cutting bulk fabric, agree how production shade, finished hand and wash performance will be judged and recorded.
What did the lab dip approve?
Imagine a buyer who approves a navy lab dip for a cotton knit and later receives production fabric that feels firmer. “Colour approved” does not say whether the finished hand, dimensional change after washing or variation across production rolls was assessed.
CottonWorks illustrates lab dipping on a specified cotton interlock substrate and describes repeated colour review before scale-up.[1] Keep the substrate, reference standard and approved sample version together. Its example does not establish the same dyeing process for every fibre or make a lab dip equivalent to finished production fabric.
Carry the reference into production, with its limits
Identify the colour standard, the chosen lab dip and the production sample by separate IDs. Record composition, construction, weight, finishing state and which face is evaluated. If the lab sample and production fabric differ, ask the mill to explain the difference and propose the appropriate next review.
Agree how bulk samples will be taken and identified by lot, roll and position, how variation will be reported and who can authorize cutting or shipment. A single swatch without its origin cannot establish uniformity across a delivery.
- 1S: colour standard; D: approved lab dip
- 2B: bulk sample; record lot (L), roll (R), position (P) and finished state
- 3Connect the reference and sample to separate shade, hand and wash records
Letters identify the illustrated references and sample. The sample count and locations are illustrative, not a required sampling plan or variation limit. Connecting lines do not imply approval.
Name the observation and measurement conditions
Datacolor describes colour decisions across lab dips and production using visual assessment and measurement.[2] Agree viewing illumination and geometry, sample backing and orientation, conditioning and the measurement setup where used. A phone photograph may help locate a problem but should not silently replace the agreed physical or digital standard.
If colour-difference results are used, record the formula, instrument settings, illuminant/observer and agreed tolerance alongside visual decisions. There is no universal pass number in this guide. Clarify how a visual/instrument disagreement is resolved, including checks under the intended lighting.
Separate the three approvals on one sheet
The following is an enquiry record, not a test standard. Use agreed methods and criteria for the actual fabric and end use. Approval of one row does not fill in the others.
| Question | Reference and conditions | Decision to record |
|---|---|---|
| Shade | Reference and conditionsStandard ID; lot/roll/position; illumination and measurement setup | Decision to recordVisual result, readings where used, accept/revise/hold and reviewer |
| Hand and finish | Reference and conditionsPhysical handle reference; finishing state; agreed comparison method | Decision to recordObservations and any finishing change still required |
| Wash and dimensions | Reference and conditionsSpecified wash/dry procedure; conditioning; measurement points; cycles | Decision to recordBefore/after results, criteria and reviewer |
| Production release | Reference and conditionsExact lots/rolls covered and unresolved exceptions | Decision to recordAuthority to cut or ship; exclusions and date |
Keep corrections visible before release
If a shade correction also changes the finish, ask whether hand or wash evaluation needs to be repeated. Do not carry approval from a different lot, substrate or finishing state into the order without an explicit review of the change.
Keep retained samples, sample IDs, results and decision dates available to buyer and mill. The enquiry can start with the intended garment, fabric specification, reference colour and hand, destination, quantity by colour and the unresolved approval questions.
Questions to send your supplier
Open supplier questions
Fabric specification / intended garment: Fibre composition, construction, weight and finishing state: Colour standard and selected lab dip IDs: Hand reference and agreed comparison method: Please propose identified bulk sampling by lot/roll/position and how variation will be reported. Viewing conditions and instrumental setup / formula / tolerance to agree: Wash/dry procedure, conditioning, measurement points, cycles and criteria to agree: Please separate shade, hand, wash results and the authority to cut or ship. List unresolved exceptions and what changes require another review. Quantity by colour and target date:
Sources
- CottonWorks — Lab Dip Process
Cotton interlock example distinguishes specified substrate/colour, conditioned measurement, iterations and scale-up. Its dye recipe, timings and chemicals are not generalized.
- Datacolor — Color Management in Textiles
Supplier explanation of colour standards, visual and instrumental evaluation, and stages of textile colour approval. Not an independent acceptance standard or proof of performance.