Product Sampling and Prototyping: Verifying Quality Before Mass Production
Golden samples, pre-production samples and AQL inspection — how to lock the quality standard before a Chinese factory starts mass production, so the first shipment matches what you approved.
Most quality disputes with Chinese suppliers do not start at the shipment stage. They start earlier, when the buyer and the factory never actually agreed on what good looks like. Sampling and prototyping is how you fix that before the machines are turned on.
The samples that matter
- Golden sample (确认样): the reference sample both sides sign off on as the quality benchmark. It should be sealed and referenced in the purchase order.
- Pre-production sample (产前样): produced on the actual production line before mass production, to confirm the factory can reproduce the golden sample at scale.
- Sealed samples (封样): physical samples sealed and kept by both parties as evidence of the agreed standard if a dispute arises.
Put the spec in writing, not just in photos
A photo is not a specification. Write down the dimensions, materials, colours (with a colour reference such as Pantone), tolerances, packaging and the standard the product must meet — a Chinese GB standard, an ISO standard, or your own written spec sheet. Vague language like high quality or good finish is unenforceable later; measurable terms are not.
AQL: the sampling language of inspection
Acceptance Quality Limit (AQL) sampling, defined in standards such as ISO 2859-1 (and China's GB/T 2828.1), is the standard way to decide how many pieces to inspect and how many defects are tolerable. Choose an inspection level and an AQL limit before production, and write them into the inspection terms. Without an agreed AQL, a third-party inspector has nothing objective to measure against.
Prototype, then a trial run
- Approve the golden sample and freeze the spec sheet.
- Order a pre-production sample from the actual production line.
- Inspect it (or have a third party inspect it) against the spec and AQL.
- Only release the deposit for mass production after the pre-production sample passes.
Attach the sealed golden sample and the written spec to the purchase order, and state that they prevail if the order text conflicts with them. This turns an informal understanding into evidence.
This content is general information about supplier verification and quality control. It is not legal advice. For a specific contract or dispute, consult a licensed attorney.
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