Prototyping in China: 3D Printing, CNC & Soft Tooling

Choose the prototype around the question it must answer

Start with the decision you need to make: does the product look right, fit together, withstand use or manufacture reliably? Define the evidence required for that decision before choosing a process.

For an enclosure, consider a printed model for grip and component placement, a machined sample for critical mating surfaces, and moulded trials for the intended resin and moulding process. Confirm that the chosen sample can support the proposed test.

The comparison below is a practical selection guide, not a China-wide price survey or delivery promise. Confirm geometry, material, finish, supplier capacity and inspection requirements in your quotation.

3D printing, CNC, vacuum casting and soft tooling compared

Cost direction describes preparation and repeat-part considerations. Quantity descriptions indicate possible project roles, not fixed process limits or minimum orders. Confirm the comparison using quotations for your design.

SLA means stereolithography, SLS means selective laser sintering, and FDM means fused deposition modelling. Here, vacuum casting means polyurethane resin cast in silicone moulds.

Define soft tooling in the quotation: specify mould material, manufacturing process and intended use. The final row concerns aluminium or similar bridge injection tooling.

How long do prototypes take in practice?

Separate manufacturing time from the time until you receive an accepted sample. Ask whether the quoted schedule includes drawing clarification, material purchasing, finishing, inspection, your feedback, international transport and customs clearance.

Compare the actual process stages rather than assuming one route is always fastest. Printing and CNC do not require a dedicated mould for the part; vacuum casting involves a master and silicone mould, while injection moulding requires injection tooling.

Request milestones for specification approval, material availability, manufacturing, inspection, dispatch and delivery. Establish what starts the clock and whether a design change creates a revised schedule.

Leave room for learning and correction. Ask which route can answer the immediate design question using the supplier’s available materials and capacity.

Get comparable quotes and define sample acceptance

Send the same revision of your model and drawings to each supplier. State the intended use, sample quantity, expected production quantity, destination, material grade, finish and dimensions that matter. Identify any permitted substitute materials.

Ask suppliers to separate design work, sample manufacture, masters or moulds, finishing, measurement, testing, packing and transport. Confirm which correction work is included and what triggers another charge. Compare quotations against the same requirements.

Set written acceptance checks for drawing revision, material evidence, critical measurements, assembly and surface condition. Use photographs for appearance review, and request separate evidence for dimensions, materials and functional performance.

Use the Chinese factory prototype guide for the sampling workflow and CNC machining cost drivers for a closer look at machining quotations.

NDAs, design files and ownership

The UK Intellectual Property Office’s NDA guidance recommends obtaining a signed confidentiality agreement before disclosure. For parties in different countries, it addresses governing law and enforcement courts. Obtain advice appropriate to the contracting parties and intended enforcement location.

Before sharing sensitive files, identify the legal business receiving them and agree the permitted purpose, authorised recipients, subcontractor access and handling of confidential information. Share what is needed for the current task.

Address ownership and usage rights separately for existing designs, paid design changes, editable files, master patterns, moulds and fixtures. Specify what must be handed over, in which usable format, and when. Do not treat sample payment as a substitute for written ownership and handover terms.

Assess manufacturing capability separately from confidentiality. Put tooling ownership, storage, maintenance, transfer and use restrictions in the relevant manufacturing or tooling agreement.

Move from prototype approval to production

Record what the prototype actually demonstrated. Limit approval to the appearance, fit, material or performance requirements supported by your checks. Assess injection-moulded properties, production consistency and product compliance separately.

Review the design with the intended production manufacturer. Check wall sections, tool access, draft, joining methods, tolerances and finishing against the chosen production process. Record accepted changes in a controlled drawing revision.

Before releasing a larger order, approve samples made with the agreed production material, tooling and process. Retain an identified reference sample alongside measurable acceptance criteria, and agree how later changes will be authorised.

For tooling budgets, ownership and transfer terms, read injection moulding tooling cost and ownership. For project scope, see the China prototyping service.

If you sell in the US or EU

US entry — sources reviewed 18 October 2026: CBP states that the importer of record remains responsible for correct entry documentation and applicable duties, taxes and fees, even when using a broker. Provide an accurate prototype description and intended use. USTR publishes China Section 301 tariff actions and exclusions; ask the broker to check classification, all applicable tariff measures and any claimed relief before shipment. Do not assume sample status establishes an exemption.

US product requirements — sources reviewed 18 October 2026: FDA states that it regulates 3D-printed medical devices through the same pathways as traditionally manufactured devices. For cosmetic or dietary supplement projects, assess the packaging and contents separately. FDA’s MoCRA guidance addresses cosmetic facility registration and product listing, including certain exemptions. FDA states that dietary supplement manufacturers and distributors are responsible for evaluating product safety and labelling before marketing.

EU product requirements — source reviewed 18 October 2026: the European Commission explains that CE marking applies to specified product categories. For covered products, manufacturers have conformity assessment, technical documentation and declaration obligations. Determine the rules applicable to your intended product before approving it for sale.

EU cosmetics and supplements — sources reviewed 18 October 2026: the Commission explains that responsible persons and, in certain circumstances, distributors must notify cosmetic product information through CPNP. Its Novel Food status Catalogue is a non-binding, non-exhaustive reference for assessing whether authorisation may be needed; it is not itself an authorisation. Assess the contents separately from approval of a container prototype.

UK worked example: a prototype sent to Cambridge

For a buyer receiving a prototype from China in Cambridge, agree the customs description and valuation evidence before dispatch. HMRC’s free-of-charge goods guidance explains how such goods, including samples, are valued for customs purposes. Free supply does not automatically establish a zero customs value.

HMRC states that the import VAT value includes customs value plus applicable duty and other additions, including relevant incidental expenses to the first UK destination. Ask the carrier or customs agent to check the actual shipment and any relief conditions. This example concerns importation into Great Britain; do not apply it automatically to other destinations.

Sources

The official regulatory and confidentiality sources below were reviewed on 18 October 2026. Manufacturer sources support the process descriptions; their capabilities and commercial terms are supplier-specific. ISO’s public abstract provides general additive manufacturing design guidance and expressly excludes process-specific and material-specific data. The table is a qualitative purchasing comparison, not an official price list, guaranteed schedule or set of universal quantity limits.