Brief a Chinese factory for a sample from a sketch

Define what the sample needs to prove

Start with the intended user, task and setting. Explain what the product holds, touches, connects to or moves against, and how it will be cleaned or stored. Include photographs of the surroundings or mating parts where useful. Say whether this sample is for checking appearance, fit, assembly or working performance.

Write down how you will assess it: fit it to the actual mating part, try the assembly sequence or check access for cleaning. Ask the factory to identify any temporary materials or construction methods that could limit those checks. The wider prototype guide covers the development route; this brief defines what the factory should build next.

Annotate views so the shape is unambiguous

Provide front, side, top and underside views wherever they reveal different features. Add a perspective sketch to explain the overall shape, and an enlarged detail or cut-through sketch for hidden joints or cavities. Label corresponding parts consistently across the views. Mark the sketch as not to scale.

Use arrows to identify openings, seams, moving parts, contact surfaces and visible faces. Explain what each feature does, rather than relying on its appearance. Label reference photographs with the feature you want to borrow, and identify anything shown that should not be copied.

Set overall size and the interfaces that matter

State overall length, width and height, with the measurement units written explicitly. Explain whether these describe the assembled, folded or open product. Locate holes, mounting points and openings from a named edge or reference surface, so the factory does not have to estimate positions from the sketch.

Distinguish a required fit from a preferred overall size. Supply the mating part or its verified dimensions where possible. If you cannot set an acceptable dimensional range, describe the fit you need and ask the factory to propose a tolerance for approval. Use the product specification guide for the broader material, finish and production specification.

Make unresolved details visible

Mark each detail as fixed, proposed or unresolved. A blank space can be mistaken for permission to choose. For unresolved materials, wall thicknesses, fastening methods or finishes, describe the result you need and request the factory's proposal, its reason and any effect on the sample's function or appearance.

Keep an open-questions list alongside the sketch. Give each question an owner and record the agreed answer in the revised brief. Ask the factory to flag conflicts between views or dimensions before proceeding. If a temporary solution is acceptable for the sample, name it and record what it cannot demonstrate.

Approve the returned drawings before making

Ask for dimensioned overall and detail drawings, with sections through hidden features and an assembly view where parts join. Request material and finish notes, proposed tolerances at critical interfaces, and a parts list for assemblies. Ask the factory to highlight departures from your sketch and explain the proposed sample-making method.

Require a drawing revision identifier and date, with matching identifiers on any accompanying model. Check the dimensions, movement, assembly access and unresolved questions against your brief. Resolve conflicting files and review translated factory drawings where relevant. Give written approval for the named revision to be made as the sample, and ask for renewed approval if it changes.

When the sample arrives, compare it with the approved drawings and record discrepancies separately from design changes you now want. Keep sample-making approval separate from tooling and bulk-production decisions, as explained in sample approval and production authority.