What to ask before choosing a custom manufacturing supplier

Buying custom manufacturing is harder than buying a product, because there is nothing to inspect before you commit. You are buying a promise about an object that does not exist, usually from a website.

These are the questions that actually separate suppliers. Several of them are ones we would rather you asked us, because the answers are a real part of what you are choosing between.

1. What exactly is in the quoted price?

The number matters less than its boundaries. Specifically: does it include the design or modelling work, how many rounds of revision, finishing, packaging, and delivery.

A quote that covers printing only, with design billed separately and revisions charged per round, can end up well above a higher quote that included everything. This is the single most common source of unpleasant surprises, and it is entirely avoidable by asking.

2. What is the lead time, and what is it measured from?

"Two weeks" is meaningless without a start point. From your enquiry? From approval of a design? From receipt of a deposit?

The honest version is usually the third, and the gap between the first and the third is where projects quietly slip. Ask what could extend it, and ask what happens if it does.

3. How many revisions are included?

Custom work involves changes. A supplier expecting zero revisions has either priced optimistically or intends to charge for reality.

Two is a reasonable norm for straightforward work. What matters more is whether you see the design before it is manufactured — approving a rendering costs nothing to change, approving a finished box of parts costs everything.

4. Who owns the design?

Ask explicitly, and get it in writing if the design matters commercially.

If a supplier models a part for you, the resulting file may belong to them unless stated otherwise. That is not necessarily unreasonable — they did the work — but you should know before you are dependent on one supplier for reorders of your own product. If you need the files, negotiate it at the quote stage where it is a conversation, not later where it is a problem.

5. What material, specifically, and can you prove it?

"Durable plastic" is not a specification. A material is a name — PETG, ASA, ABS, PLA — and a supplier should be able to say which and why.

Push further if it matters. If a part must survive heat, sunlight or food contact, ask what it is being made from and what evidence supports the claim. Anyone who will not name the polymer is not someone to trust with a part that has requirements. Our own figures and caveats are on the materials page, including what we will not claim.

6. What happens if a part fails?

Ask before you need to know.

A reasonable supplier will replace something that failed because of how it was made. The more revealing question is what happens when a part fails because of how it was *designed* — by them, to your brief. That is where you learn whether you are buying a manufacturer or a printing service.

7. Have you made something like this before?

Not to check credentials, but to find out what they learned. A supplier who has made something similar will volunteer the problem you have not thought of — the stress point, the tolerance that matters, the finish that will not survive handling.

A supplier who says every job is straightforward has either not done many or is not paying attention.

8. Where is it actually made?

Worth asking plainly, because the answer affects far more than principle.

Local manufacturing means you can visit, revisions take days rather than shipping cycles, and there is no customs step between a problem and its fix. Overseas manufacturing is often cheaper per unit and slower to correct.

Neither is wrong. But compare landed cost and total elapsed time, not unit price — shipping, duty and a four-week round trip on a revision are part of what you are buying. We make in Malta and in Italy, which is a genuine advantage on iteration speed and a genuine disadvantage on price at high volume. Both are true.

9. When would you tell me not to use you?

The most useful question on the list, and the one that gets the most informative answer.

A supplier who can immediately name the jobs they are wrong for is describing a real business with real limits. One who says they can do anything is either very large or not being straight with you.

For us the answer is specific: thousands of identical units, anything safety-critical, anything requiring certification we do not hold, and anything running above roughly 100°C. We would rather turn those down than take them. The reasoning is in 3D printing or injection moulding.

What makes you easy to quote for

Suppliers give better prices and better advice to buyers who arrive with clarity. Not detail — clarity:

• What the object does, and where it lives
• Quantity, and realistic quantity over a year
• The actual deadline
• Any requirement it must meet: load, heat, contact, regulation
• Whether the design is settled

That is enough for a serious answer from anyone worth buying from. If a supplier needs more than that before they will engage at all, that is data too.