A die-cut part is often the cheapest line on the BOM and the most expensive thing on it to get wrong. A gasket 0.2 mm out of place stops a line at two in the morning. So the decision cannot come from a price sheet: a quote says what a supplier hopes the job will cost, the process says what happens when it goes wrong.
Why cheap quotes get expensive
When one quote lands 30 percent under the field, the difference is rarely efficiency. It is one of three things, all paid for later.
A cheaper grade. "Equivalent" is the word to watch. A 0.15 mm acrylic foam and a 0.15 mm PE foam cut identically and behave nothing alike under compression; the saving returns as a seal with permanent set.
A wider tolerance, quietly. A worn die, a faster press, an operator sorting by eye. Nobody measured, so it passed.
Inspection that was never costed. Sampling at a loose AQL suits a cosmetic part and fails a sealing one. Quoting sampling while implying full inspection is a misrepresentation, not an economy. At a million pieces a year, 0.015 USD is 15,000 USD; one stopped line costs more in a night.
The 8 checks
Each can be settled in one email; none requires travel.
1. Are they a converter or a trading company?
Ask for a live video walkthrough — press floor, die rack, inspection bench — with your part's route pointed out. Ask for the business licence and read the registered scope: manufacturing, or only trading. Ask which press will run your part and who sets the die. A trader is not disqualifying, but know which you are buying from: part of the price is their margin, and the quality answer belongs to a factory you never speak to. Our factory background is on the about page.
2. Can they show the material grade and mill?
Send one line: "Confirm the exact grade, thickness and manufacturer, and attach the TDS." A converter answers with a grade code and a mill name. A reseller answers "equivalent to" and hopes you move on. Grade codes matter: two foams of the same density can differ in compression set and outgassing. Ask for a photo of the roll label with the lot number. For RoHS and REACH, the conformity declaration comes from the material supplier and ships with the goods. Our eight categories are on the products page.
3. Tooling: who owns it and who keeps it?
Three questions, in writing. Is the die charged once, or again on every repeat? Where is it stored between runs, and for how long? If I move to another supplier, can I take it, and at what price? Add a fourth: on a revision, modification or new die? Normal practice is a one-time charge, no repeat fee on the same drawing, modification quoted before work starts. Insist the die is its own line, never amortised into the price. If ownership is vague, assume the die is theirs.
4. Tolerance capability versus your drawing
Ask two numbers before you send anything: standard tolerance, and minimum feature size. Ours is ±0.15 mm typical, with features down to roughly 1.0 mm depending on material and process. Then ask for a first article report with measured values, not a form with "pass" ticked. A supplier who cannot produce numbers on a sample will not produce them on a lot. Circle the two or three dimensions that function, and ask what happens when one is missed, and who pays for the sort.
5. Inspection: sample or 100%?
Is outgoing inspection AQL sampling or full inspection? Which level, which defect classes? What ships with the lot — check sheet, dimensional report, both — and who signs it? If a bad part stops your line, ask for 100% and a report per lot, and expect to pay for it. We inspect 100% before shipment and issue dimensional reports on request. We hold no management-system certificate, so the documents carry the weight — ask every supplier, us included, what stands in for it.
6. Sampling terms, in writing
"Free sample" is the most expensive phrase in sourcing. Ask for the whole sentence: charge per piece, who pays freight and duty, lead time in business days, and whether the charge is credited against the first PO. Then ask how it was made — production tooling, or hand-cut. A hand-cut sample proves nothing about a steel rule die. Ours are charged, freight at the buyer's cost, 3–5 business days for standard parts, both stated in the quote. A free sample with no material code is not free.
7. The communication loop
Ask who the engineer is. Not the sales contact — the person who will read the drawing. Will DFM feedback come before the quote or after the order? What response time is committed, in which time zone? A supplier who quotes first and asks afterwards is guessing, and you settle that guess at first article. Before the PO you want one named engineer, one thread, and one question from them you had not thought of. A good engineer asks about your assembly, not only your dimensions.
8. Change control and traceability
How does a material substitution get approved, who signs it, and do you hear before or after? Ask for the die maintenance log and what triggers a re-cut. Ask what the box label carries, and whether that lot traces back to material lot and inspection record. Then test it: pick a shipment from six months ago and request its paperwork. A supplier with a system answers in a day. One without answers with another question. No lot number means no trace, and no trace means no recall scope.
| Check | What to ask | Red flag |
|---|---|---|
| Converter or trader | Live video of the floor; licence scope; which press runs my part | Office address only; recorded brochure video; factory in another city |
| Material grade | Grade code, mill name, TDS, roll label photo, conformity declaration | "Equivalent to" with no code; grade changes between sample and bulk |
| Tooling | One-time charge? Repeat fee? Storage? Ownership on transfer? | No tooling line; unit price "includes" the die |
| Tolerance | Standard tolerance, minimum feature, FAI with measured values | Only "as per drawing"; FAI with pass/fail tick boxes |
| Inspection | AQL or 100%, defect classes, report type, signatory | "We check every batch", with no document to show |
| Sampling terms | Charge, freight, business-day lead time, production tooling? | "Free sample", then a tooling charge appears on the PO |
| Communication | Named engineer, DFM before the quote, response time | Quotes without questions; answers only from a sales inbox |
| Change control | Substitution approval, die log, lot traceability | Material swapped without notice; no lot number on the label |
What to put in the RFQ to test a supplier
One small order tests more than a factory tour. Send a drawing with one functional dimension at ±0.10 mm, one feature near 1.0 mm, a material target and your inspection requirement. Then watch: did the DFM note arrive before the price, flagging the hard feature; did the quote break out grade, tooling, sample cost and validity; did the sample land in the promised days, off the production die; did the FAI carry measured numbers?
You are not buying a sample. You are buying evidence of how the next thousand pieces will be handled when nobody is watching.
Red flags in the quote itself
- No separate tooling line. Folded into the price, the die is paid for on every reorder and owned by nobody when you leave.
- No validity date. Material is indexed to resin markets; a quote that never expires was never calculated.
- No material grade. "As per drawing" means the grade is picked at the press.
- Tolerance "as per drawing" when your drawing states a general tolerance. Nobody read it, only the outline.
- A lead time half the market's. Custom parts are not in stock: the date is fiction, or inspection was cut to hit it.
| Score | Price | Tooling clarity | Material spec | Inspection | Lead time |
|---|---|---|---|---|---|
| 3 | Within 10% of the median, with quantity breaks | Separate line, one-time, no repeat fee, ownership stated | Grade code, mill, thickness, TDS attached | Method, level, report type and signatory named | In business days, counted from tooling approval |
| 2 | Lowest, with no breakdown | Separate line, repeat fee unclear | Generic family only, e.g. "acrylic foam" | "Full inspection", no document | Stated, but shorter than the sample actually took |
| 1 | Far below the field, or identical at every quantity | None, or "included" | "Equivalent" or "as per drawing" | Nothing, or visual only | Half the field, or "to be confirmed" |
Weight inspection and material spec double if the part seals.
FAQ
Do I need to visit the factory?
Not necessarily. A live video call through press floor, die rack and inspection bench covers most of it. Visit if the part is safety-related, the value is high, or this is your first order. If you go, ask to see your die and the last lot's paperwork.
How do I verify material grade without lab testing?
Not fully, and anyone who says otherwise is selling. Match the TDS to the grade code on the roll label, keep the supplier declaration with the shipment, and test the finished part against the performance you need. Where the claim is critical, a lab test is cheaper than a recall.
What is a reasonable sample lead time?
Three to five business days for a standard single-layer part once drawing and tooling are confirmed; longer for laminates. A 24-hour sample is hand-cut or ex-stock — ask which. Get the number in business days, with the tooling fee beside it.
Can a Chinese supplier sign an NDA?
Yes, most sign under Chinese law, in English or bilingual. The practical questions matter more: who inside can open the drawing, and are files deleted at the end?
Send a drawing with a tolerance on it to our RFQ page. You get a material recommendation, unit price, tooling fee and DFM feedback within 24 hours — and if a feature cannot hold what you asked for, you hear it then, not at first article.
Further reading
