Every supplier looks identical on a listing page: same renders, same claims, same “professional manufacturer since forever”. Vetting is the skill of making them differ. Here is a working checklist, ordered by cost — questions first, visits last.

Stage one: questions that separate quickly

Ask category-specific technical questions: which knit machines and gauge for this legging, what reduction percentage would you start with for this fabric, how do you test recovery after wash. Fluent, specific answers within a day signal a real technical team; brochure language signals a listing operation.

Ask who actually makes the product. An honest factory names its lines; an honest supply chain manager names its model — SEAMDANCE, for instance, states plainly that independent specialist partners produce, and we manage. Evasion on this question is the loudest answer you will get.

Stage two: paper that must exist

Business license matching the name you are paying; certificates with scopes and facility addresses that match where your product will actually be made (an OEKO-TEX certificate for a mill in one city does not cover sewing in another); test reports for the actual fabrics proposed; and references in your market — with permission to contact one.

Read certificate scope lines carefully. Valid-looking certificates covering the wrong site or the wrong process are the most common paper trick in apparel sourcing.

Stage three: the sample tells the truth

Order a paid sample of a style close to your product before any commitment. Read it like an inspector: interior finish (loose threads, uneven flatlock tension, raw label edges), measurement accuracy against a stated chart, wash behavior after three cycles, and whether the accompanying documentation — spec sheet, fabric details — arrives unprompted.

Speed and communication during the sample are the rehearsal for bulk. A supplier who is slow and vague while courting you will not improve after the deposit. For calibration: stock samples from SEAMDANCE ship in 3–4 days, custom first samples normally in 7, with the spec attached.

Stage four: design a pilot that measures

Structure the first order small but real — stock programs from 100 pieces exist exactly for this. Fix measurable expectations upfront: inspection standard (AQL 2.5 is the industry's common level for apparel), delivery date in writing, defect remedy agreed before production, not after.

Then measure: on-time or not, inspection pass rate, communication latency, documentation quality. Two clean pilots earn scale; one excused failure predicts the next.

Quick answers

What is the single strongest signal in vetting?

Specificity under pressure. Vague answers to precise technical and accountability questions predict every later problem. Specific answers, including honest 'no, we cannot do that' — predict a workable partner.

Should I visit before ordering?

For large programs, yes — or commission a third-party audit. For pilot-scale orders, a paid sample plus document verification plus a video walkthrough of the actual facility is a reasonable proxy.