What should buyers check before bulk approval?
Before approving bulk production, ask for the sample identity, test method, washing and drying conditions, measurements before and after laundering, and the acceptance requirements agreed for your order. Review each relevant measurement separately and record who approves the result.
A message saying “shrinkage is 2%” leaves several decisions open. Which dimension changed? Was the test performed on fabric or a complete garment? What washing and drying conditions were used? Does the sample represent the material and construction planned for production?
For clothing brands buying T-shirts, hoodies or other custom apparel, those details connect a test result to a purchasing decision.
Identify the sample and the approval it supports
Begin with the physical sample. Record its style, size, color, material reference, finishing route and specification revision. Identify any substitute fabric, rib, label or construction detail that differs from the intended product.
“Pre-shrunk,” a production wash description and a documented laundering result provide different information. A stone-wash or enzyme-wash specification describes a manufacturing process. To assess dimensional change under consumer-care conditions, request the relevant laundering test and its recorded conditions. Our garment wash guide explains production wash choices.
Also agree which condition the measurement chart describes: before laundering, after a specified test, or both. This prevents the team from comparing results taken at different stages. Use the pre-production sample checklist to keep dimensional approval alongside the other sample decisions.
Check whether the report covers fabric or a garment
The public scopes of AATCC TM135-2025 and AATCC TM150-2025 distinguish fabric dimensional-change testing from garment testing. TM150 also identifies an applicability limitation for certain stretch-fabric garments; ask the testing provider to confirm the method for your product.
A fabric report can inform material selection, but it does not provide measurements of the finished garment’s sleeves, body or assembled details. If the intended approval concerns the complete garment, confirm what additional evidence is needed.
Carry the approved material reference from the fabric-sourcing brief into the test request. A report for an unidentified swatch gives the buyer little basis for connecting its result to the current sample.
Write a test request the provider can act on
Agree the following fields with the supplier and testing provider before testing. This is a buyer communication checklist; the provider should use the full applicable method to establish laboratory procedures.
| Field | What to confirm |
|---|---|
| Object and identity | Fabric or garment; sample reference, style, size, color and current revision |
| Production relationship | Intended material and finish; substitutions and limits on applying the result to bulk |
| Method | Name, edition, product suitability and any departures from the method |
| Laundering conditions | Washing and drying procedures, repetitions and relevant equipment, temperature and detergent details |
| Measurement record | Defined points, units, original dimensions and dimensions after the specified treatment |
| Acceptance | Order-specific requirements for each relevant point and measurement stage |
| Responsibility | Report reviewer, approval authority and next action if information or results are unacceptable |
The public scope of ISO 6330:2021 addresses washing and drying procedures and notes that parameter differences can affect results. Record both parts of the treatment when reviewing or comparing reports.
Choose sample quantities and repetitions with the provider according to the product, risks and agreed method. The number of agitation options listed in a method summary should not be read as a requirement to repeat the wash that many times.
Read the dimensions, then calculate the change
The same measurement point needs identifiable start and end positions. Ask for the preparation and measurement conditions as well as the values. ISO 3759:2011 covers preparation, marking and measurement for dimensional-change assessment. ISO 5077:2007 addresses dimensional change after specified washing and drying treatments.
For understanding proportional change, use this illustrative calculation:
Change (%) = (after − before) ÷ before × 100
The invented values below explain the arithmetic. They are not customer, production or laboratory results, an acceptance standard, or Wincome Apparel’s default specification.
| Defined measurement point | Before | After | Change |
|---|---|---|---|
| Body length, with agreed endpoints | 70.0 cm | 68.6 cm | −2.0% |
| Half chest, measured flat | 60.0 cm | 60.6 cm | +1.0% |
The length calculation is (68.6 − 70.0) ÷ 70.0 × 100 = −2.0%. A negative value indicates a decrease; the chest example has a positive value because it increased. If a report expresses shrinkage as a positive percentage reduction, confirm that sign convention before comparing results.
Keep the points separate rather than averaging them. The two percentages describe different dimensions and must be reviewed against their respective requirements. Neither result establishes a pass without those requirements.
Agree acceptance before deciding on bulk
A method identifies how the test is performed. The order agreement identifies what the buyer will accept. Confirm requirements before reviewing results rather than assuming a universal percentage for every fabric, garment and market.
Keep dimensional change separate from the manufacturing tolerance around a target measurement. For example, permission to vary around an agreed pre-laundering length does not automatically define the acceptable change after laundering. Record both requirements where they are relevant. The size-grading guide explains how garment targets, grade increments and measurement tolerances work together.
If requirements are missing, ask the responsible buyer and technical parties to establish them. Preserve the measured result while the acceptance decision remains open.
Turn the report into a recorded decision
| Report situation | Buyer’s next step |
|---|---|
| Representative sample, complete conditions and results within agreed requirements | Record approval for this test item; review the remaining production approvals separately |
| Only a percentage or “wash tested” statement | Request sample identity, measurements, method and laundering conditions |
| Fabric evidence provided for a garment-level decision | Ask the provider to identify the remaining garment evidence needed |
| Conditions or sample differ from the intended approval | Clarify applicability and whether representative retesting is needed |
| A relevant point falls outside the agreed requirement | Hold approval for that item, agree corrective work and review the resulting evidence |
When an adjustment changes material, finish or garment construction, record the revised reference and review its fit and test requirements. Keep the report, measurement chart, specification revision and approval note together for the production team.
This proposed decision framework does not guarantee every unit in a shipment. Bulk checks remain part of the garment inspection plan.
Sources and scope
Technical references checked October 2, 2026: the public scopes of ISO 6330:2021, ISO 3759:2011, ISO 5077:2007, AATCC TM135-2025 and AATCC TM150-2025. These references establish the limited method scopes discussed here. The testing provider should confirm applicability and use the full relevant procedure.
The checklist, invented calculation example and decision table are Wincome Apparel’s explanatory buyer guidance. They are not excerpts from a standard or evidence of a completed test or customer order.