Tooling: Stock Mold or Custom Mold, and What Decides It
Molds decide unit cost, cosmetic quality, how fast a programme can move and whether a bottle stays exclusive to your brand. Ours are designed, cut and maintained in our own mold shop.
Most projects should start on a stock mold; a custom mold is for a shape or an exclusivity requirement
A stock mold already exists, so it can run immediately at MOQ from 5,000 pieces and with no tooling charge. A custom mold is built to your drawing or sample, which is what a genuinely new shape, a branded profile or an exclusivity requirement needs.
The decision is not about quality — both routes produce to the same specification and the same inspection plan. It is about whether an existing cavity can give you the shape you need, and whether you need the shape to be unavailable to anyone else.
This page covers tooling as a manufacturing decision: stock versus custom, the development sequence, sampling, mold ownership and lead time. For the bottle geometry that the tool has to produce, see bottle design.
Stock mold vs custom mold vs private mold
These three terms get used loosely. Here is how we use them, and what each one commits you to.
| Stock mold | Custom mold | Private mold | |
|---|---|---|---|
| What it is | An existing cavity in our library that already matches a capacity, material and neck finish you can use | A mold built to your drawing or sample, which may be a new shape or a variant of a stock geometry | A custom mold that is built for one programme only and never used for another customer |
| Tooling charge | None — the tool already exists | Quoted against the part, the cavity count and the tooling schedule | Quoted against the part; terms are set out in writing before you commit |
| Typical first-order quantity | From 5,000 pcs per SKU | Larger first order, typically in the 10,000–20,000 piece range, because the tool has to be amortised | Agreed per programme with the tooling terms |
| Sampling window | 3–10 days on an existing mold | Confirmed up front, before you commit — the tooling schedule is agreed rather than estimated after the fact | Same as custom; the tooling and sampling schedule is agreed in writing at quotation |
| Exclusivity | None. The same cavity may run for other customers, including in other colours | Depends on the terms agreed. Say if exclusivity is required and it will be written into the quotation | The mold is built and held in-house for your programme and is not resold or reused for another customer |
| Best for | Speed to market, low first-order risk, proven geometry, market testing | A shape no stock cavity provides, a specific brand profile, or a specific technical geometry | A brand whose whole proposition depends on the bottle being unavailable elsewhere |
If you are not sure which applies, send the drawing or the sample. We will tell you whether a stock cavity can serve it — and if it can, that is usually the faster and cheaper answer, which is why we will say so rather than quote a tool.
The mold development sequence
Tooling is the stage where a design change costs the least and a late change costs the most, so the sequence below puts the reviewable decisions before the irreversible one.
Drawing or sample review
We start from a dimensioned drawing, a 3D file or a physical sample. A sample is often faster when the design is already fixed, because it can be measured rather than interpreted.
Read the guide →Design-for-manufacture feedback
Before a tool is quoted we tell you what will and will not mold reliably: blow ratio, wall distribution, undercuts, handle geometry, neck placement and the features that will show sink marks. This is the cheapest conversation in the project.
Tooling quotation and schedule
The tooling charge, the cavity count and the sampling schedule are confirmed in writing up front, including the terms that apply to exclusivity and to ownership.
Mold build
The mold is designed, cut and assembled in our own mold shop. Keeping this in-house is what makes a private mold genuinely private, and what keeps repairs from stopping production.
T1 first article
The first shot off the new mold is the reference for the whole run. It is measured, compared against your drawing and, where colour is involved, compared against a physical master sample.
Sample approval
You approve the sample. This is the point at which the specification stops being a document and becomes the standard that production is inspected against.
Pilot run and handover
A short run confirms the process window holds over more than one shot, then the tool moves into normal production with the same inspection plan as any other part.
Stock-mold samples typically ship in 3–10 days. Where new tooling is required, tooling plus sample runs are typically quoted at 15–30 days — and the schedule is confirmed against your specific geometry rather than assumed from that range.
What actually decides a tooling specification
These are the variables that move when a bottle changes. Each one is a cost, a quality risk or both, which is why they are settled at design stage and not at sampling.
Tooling considerations
Mold ownership, exclusivity and what we do not promise
Tooling terms are commercial terms, and commercial terms belong in a quotation rather than in a paragraph designed to sound reassuring. What we can state plainly is how we operate.
- ▸Private tooling is built and held in-house for your programme. It is not resold, and it is not reused to make the same bottle for another customer.
- ▸Tooling stays confidential. Your drawings, samples and geometry are treated as your information, and the mold is numbered and stored against your programme.
- ▸Repairs do not leave the building. Because the mold shop is on site, a repair does not wait on a third party’s queue.
- ▸Exclusivity is written, not implied. If a bottle has to be unavailable to anyone else, say so, and the exclusivity term goes into the quotation.
- ▸Tooling charges, ownership and any transfer terms are set out in writing before you commit. Ask for them at quotation stage and you will get them in writing.
We do not advertise a free-mold programme or lifetime mold ownership. Any tooling charge, ownership position or transfer arrangement is a commercial term, and it is confirmed in writing against your specific project rather than offered as a standing policy.
If your project depends on a tooling arrangement we cannot offer, we will tell you at quotation stage instead of discovering it after the tool is cut.
This is the same discipline we apply to quality claims: a statement that cannot be supported by a document is not a statement we make. See quality & compliance for how we distinguish a certification from a test report from a compliance statement.
What decides tooling lead time
Tooling lead time is not a fixed number, and a supplier who quotes one without asking about your part has not looked at your part. These are the variables that actually move it.
| Variable | Why it moves the schedule |
|---|---|
| Whether the geometry needs rework before it can be cut | A design that has to be adjusted for blow ratio or wall distribution adds a review cycle before the tool is even quoted |
| Whether the neck finish is already fixed and matched to a real closure | An open neck finish means the closure has to be sourced or confirmed first, and the tool cannot be finished until it is |
| Cavity count | More cavities means a larger tool block and a longer build, but more parts per cycle once it runs |
| Surface finish | A textured or matte cavity takes longer to cut and finish than a gloss one |
| Sampling rounds | Each round of sample approval is a cycle. Approving quickly is the single largest lever a buyer controls |
| Colour and master sample approval | Where colour matters, production cannot be released until the physical master sample is signed off by both sides |
| Machine slot availability | Tooling and blow or injection capacity have to line up, so the schedule is confirmed against both rather than one |
| Engraving and brand marks | Mold numbers and any brand engraving are cut into the tool and verified at first-article stage |
The practical advice: fix the neck and closure first, approve a physical colour sample early, and give us the drawing or the sample in the first message. Those three things remove most of the schedule risk that a tooling project carries.
Tooling FAQ
Do I need a custom mold to get a bottle in my own shape?+
Not always. There are 2,000+ stock molds across PET, PE, HDPE and PETG, many of which already match common capacities and neck finishes. A stock cavity runs at MOQ from 5,000 pieces with no tooling charge, so it is normally the right place to start. A custom mold is for a shape no stock cavity provides.
How much does a mold cost?+
It depends on the part, the cavity count and the material, so it is quoted per project rather than published as a price list. Send a drawing or a sample and you will get a tooling quotation with the schedule and the terms in writing.
Who owns a private mold?+
A private mold is built and held in-house for your programme and is not resold or reused for another customer. Ownership, storage and any transfer terms are commercial terms and are set out in writing in the quotation. We do not advertise a free-mold programme or lifetime mold ownership.
How long does sampling take?+
Stock-mold samples typically ship in 3–10 days. Where new tooling is required, tooling plus a sample run is typically quoted at 15–30 days, and the schedule is confirmed against your geometry rather than assumed from that range.
Can you copy a bottle we already buy elsewhere?+
Send a sample and we will measure it and tell you what a tool for it would involve. If the geometry is protected by a design registration, that is your responsibility to clear — we will ask before we cut anything.
What happens if the first sample is not right?+
The first shot off a new mold is the reference for the whole run, so it is measured against your drawing rather than judged by eye. If it is out, the tool is corrected and re-sampled before production is released.
Can you maintain a mold you did not build?+
In many cases yes, but it depends on the tool. Send the drawings or the tool itself and we will assess it before committing to production from it.
Tooling, bottle design and production
Tooling sits upstream of the eleven production stages: it is what makes stage 03 and stage 04 possible at all.
Send us the drawing or the sample.
We will tell you whether a stock cavity can serve it, what a tool would cost, and what the sampling schedule looks like.
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