Red flags, ranked by how much they tend to cost
These are the signals worth weighting heavily, with the most expensive first. They are listed as judgements to apply, not as disqualifications, because a young supplier can have one of them and still be excellent. What matters is whether they correct it when you name it.
A lead time shorter than the method physically allows. Decoration methods have real minimum durations, and the quote compresses them below that floor. It is the most common way an optimistic quotation becomes a late delivery, and it usually emerges around the day the order should have shipped.
A refusal to name who decorates the goods. Brokers exist and are legitimate, but a broker who will not tell you whether they own the operation is hiding something you would want to know. Ask the question directly and accept a direct answer either way. The problem is the evasion, not the answer.
A garment specification that names a brand instead of a construction. A brand name tells you nothing you can verify, and it changes between seasons. Weight in grams per square metre and fibre composition tell you everything. Suppliers who genuinely control their product describe it in the second way.
An artwork process conducted entirely in chat. Files arriving with no version numbers, approvals given in messages, and no single approved master is how orders get decorated from a superseded file. This is invisible on the sample and expensive at volume.
A single unit figure with no breakdown. One number covering garment, decoration, packing and delivery cannot be improved later, because there is nothing to negotiate against. It also hides the fact that the supplier has not decomposed your specification at all, which means the number is a guess attached to your order rather than a quote for it.
A specification that changes after the order is placed. Substituting the garment fabric, the thread colour or the carton type once the order is in production is the mechanism by which the delivered goods stop matching the approved plan. It is sometimes unavoidable and always acceptable if disclosed before production, and never acceptable if disclosed after the cartons are sealed.
A unit price far below the market floor. There are only a few explanations: a different and cheaper garment, a different and cheaper process, a much larger volume assumed than you stated, or a quotation that will be revised upward later. Ask which one, in writing, and treat an evasive answer as the answer.
A reference offered only in a moderated setting. If the supplier insists on joining the call and steering the conversation, you have learned something about how they handle problems as well as how they handle references.