Order Quantities: Public-Mould Case vs Custom-Tooled Case

"What's your MOQ?" is the first question most buyers send a moulder, and the minimum order quantity for silicone protective cases is close to the least useful thing you can ask about first. The number that comes back is a sales estimate covering an unknown mix of assumptions — one colour or four, plain or printed, existing tool or new one, first order or repeat. Change any one of those and the honest answer changes with it.

Order quantity for a moulded silicone or plastic protective case is not a policy. It is an output of setup economics. Understanding which setups you are paying for tells you where a small first order is realistic, where it is expensive, and where custom tooling stops making sense at all.

One note on this factory specifically before going further: the trading-terms table on WJM Silicone's CMH page leaves the MOQ field blank, and no figure is published. This article deliberately quotes no minimum quantity for that factory or any other. What it gives you instead is the structure to ask for, so the number you get back is one you can actually compare between suppliers.

What actually sets a minimum

Five setup events sit behind any quoted minimum. Each one is a fixed cost that has to be spread over the run.

Tool setup on the press. Hanging a mould, bringing the press to temperature and running to a stable part takes the same time whether you then mould 500 pieces or 50,000. Silicone compression and plastic injection both carry this, and on short runs it dominates every other setup cost.

Colour changeover. This is the one buyers underestimate. Each colour is a separate material preparation and a separate purge; going from a light colour to a dark one is cheaper than the reverse, and a translucent or fluorescent shade may need a dedicated batch. Four colours in a 4,000-piece order is not one 4,000-piece run. It is four runs, four changeovers, and four colour-match approvals.

Material lot minimums. Coloured silicone compound is mixed to a masterbatch or pigment loading. Below a certain weight the mixer produces a batch you cannot fully consume, and the remainder is either scrapped or charged to you. This is why a small order in a custom Pantone frequently prices worse per unit than a larger order in a stock colour.

Decoration setup. Pad printing needs a plate per colour per position. Laser debossing needs programming and fixturing. Both are one-time per SKU per run, and both are commonly buried inside a unit price where you cannot see them.

Inspection and packing. Sampling plans, carton and inner-box minimums, barcode label rolls with their own order minimums.

Notice what is not on that list for a public-mould part: the mould. That absence is the whole story.

Two routes: public mould versus custom tooling

The public-mould case

WJM maintains 80+ ready-made public moulds for POS terminal cases, with samples from an existing tool in as little as 72 hours and near-zero upfront mould cost for standard models. Where your device is covered by one of those tools, the biggest fixed cost in the project — the mould — is already sunk, and it was not sunk by you.

That changes the shape of a first order in three ways.

You can start smaller, because the quantity no longer has to justify a tooling investment. How much smaller depends on the setup items above, not on the tool. Ask the question as "what is the smallest run that makes sense in one colour, undecorated?" and then price each addition separately.

You can validate before you commit. A 72-hour sample from an existing mould means fit and hardness are confirmed against your actual device inside a week. That collapses the risk of a first order — you are ordering a part you have held.

Your constraints move to colour and decoration. On a public-mould part, the colour changeover minimum and the print setup usually are the MOQ. That is why the colour-changeover minimum per SKU is the number worth asking for by name; it is not published, and it will do more to shape your first PO than any headline figure.

What you give up is exclusivity. A public mould is factory-owned tooling that other buyers can order from. Whether one can be reserved is not published and should be asked directly — and it is a separate question from who owns a tool you paid for, which is covered in who owns the mould after you pay for it.

The custom-tooled case

Custom tooling is justified by arithmetic, not by preference. The arithmetic is simple enough to do on the back of the RFQ.

Tooling cost T, spread over quantity Q, adds T ÷ Q to every unit. Against a public-mould alternative priced at P_public and a custom part at P_custom, custom tooling is worth it when:

(P_public − P_custom) × Q > T

Or, more usefully for planning: the tooling recovers itself at Q = T ÷ (P_public − P_custom).

The numbers below are placeholders illustrating the method. They are not a quote from any factory — put your own tooling quote and your own price delta in before drawing any conclusion.

That last row matters. Most custom tooling in this category is not justified by unit price at all — it is justified by a device with no public mould, a fit tolerance the public shell will not hold, thermal venting the public shell does not have, or a shape you want competitors locked out of. When the case for custom is strategic rather than arithmetic, say so internally, because it changes how you evaluate the payback.

Two further items to pin down before signing a tooling PO: the tooling lead time to first article, which is not published for this factory and belongs in the schedule; and the ownership terms, because a tool you paid for and cannot move is a weaker asset than the invoice suggests. The general cost landscape is in what tooling and mould costs actually look like in China.

Ask for a quantity table, not a minimum

Replace the MOQ question with a request the supplier can answer precisely and you can compare across three quotes. Send this grid and ask them to fill it:

Three things happen when you send this. You find out fast whether you are dealing with someone who runs presses or someone relaying your questions — a moulder fills it in, a layer negotiates about it. You get a document you can put side by side with two competitors without translating anyone's assumptions. And you surface the changeover and setup lines that would otherwise hide inside a single unit price, which is where most of the negotiating room actually lives. The tactics for that conversation are in how to negotiate a minimum order quantity with a China factory.

Where custom stops making sense

Four situations where a buyer should stop and re-check before authorising tooling.

Your device is already covered. Send the exact model designation, not the brand family, and ask for a photo of the existing tool or a part moulded from it. A public mould that fits is worth more than a custom tool that is three weeks away.

The device is late in its refresh cycle. Payment terminals and rugged handhelds get replaced on multi-year cycles. Tooling amortised over a model that goes end-of-life in twelve months does not recover, however good the per-unit maths looked.

Your differentiation is on the surface, not the shape. Colour, hardness, grip texture, logo placement and packaging are achievable on a public shell. If nothing about your requirement changes the geometry, custom tooling buys you exclusivity and little else — decide whether exclusivity alone is worth T.

Volume is uncertain. Tooling converts a variable cost into a fixed one. A hybrid path — start on a public mould, prove the sell-through, then tool once the volume is real — costs a little more per unit early and removes the biggest single risk in the programme.

Against those, the situations that genuinely require custom tooling are worth naming too: a device with no public mould in any library; a tolerance or port-cutout requirement the public shell cannot hold; thermal venting or heat-dissipation structure the public part lacks; a multi-material or overmoulded construction combining, say, TPU over PC; or an automotive interior part where the geometry is specific to one vehicle.

Common questions

Why won't a factory just publish an MOQ?

Because a single number would be wrong for most enquiries. The realistic minimum for a one-colour undecorated part from an existing tool and a four-colour printed part on new tooling are different by an order of magnitude. WJM's trading-terms table leaves the field blank rather than publishing a figure that would mislead — ask for the quantity table instead and you get something you can hold them to.

Can I mix colours within one order to hit a quantity break?

Sometimes, but ask how it is priced. The total order may reach a volume tier while each colour still carries its own changeover and its own minimum run. Get the colour-changeover minimum per SKU stated separately so you can see which mixes are cheap and which are not.

Does the minimum drop on a repeat order?

Ask, and get it in writing at the first PO. Repeat runs skip artwork approval, colour matching and first-article inspection, which is real cost removed. Whether that translates into a lower minimum at this or any factory is not published, and it is much easier to agree before the first order than after.

What to ask the supplier next

1. Is my exact device model covered by an existing public mould? Send a photo of the tool or a moulded part.
2. Fill in the quantity table above — tiers, colour count, changeover minimum, decoration setup, packaging minimums, lead time at each tier.
3. State the colour-changeover minimum per SKU as its own number, separate from total order quantity.
4. Quote decoration (pad print, laser debossing) as setup plus per-piece, not folded into unit price.
5. If custom tooling is required: tooling cost, cavity count, lead time to first article, and the ownership and release terms.
6. Sample cost and lead time, and whether the sample charge is credited against a production order.
7. Confirm whether the minimum changes on a repeat order of the same SKU and colour.
8. Confirm the material by name — food-grade silicone, industrial silicone rubber, TPU, PC or ABS — since compound choice affects both price and colour minimums.

WJM Silicone is a useful test case for the two-track comparison: 80+ factory-owned public POS moulds on one side, with sampling in as little as 72 hours and near-zero upfront tooling for standard models, and full OEM/ODM custom development on the other, covering shape, colour, logo, texture and port placement. Ask for both quotes on the same enquiry — the public-mould price and the custom-tooled price with tooling shown separately — and the break-even calculation makes itself. For a wider view of how MOQ and lead-time data varies across Chinese factories, see what sourcing data on MOQ and lead times actually tells you.