Jewellery CAD Weight Estimates vs Finished Weight: What to Agree

A jewellery CAD weight estimate is useful when a designer is comparing proportions or a retailer is preparing a quotation. It is still an estimate of a specified model. It should not silently become a promise about the weight of a completed piece with stones, findings and finishing included.

The practical question is what the number represents. A clear weight record identifies the model revision, the material assumption and the components included. Without those details, two apparently conflicting estimates may simply be measuring different things.

Start with the geometry being measured

Ask which objects were selected for the calculation. A model might contain alternative heads, duplicated components or stones used only for visual reference. Conversely, a separately supplied back or clasp might be absent. The person preparing the estimate should identify these boundaries before reporting a total.

McNeel's Volume documentation confirms that Rhino reports volume for selected supported objects. That geometric result is not, by itself, a finished jewellery weight. It needs an appropriate material assumption and a clear account of what the model contains.

Name the alloy assumption

Record the proposed alloy rather than a colour description such as white metal. Converting volume into estimated metal mass depends on the density used. Ask the supplier or modeller to state that assumption; do not insert a universal value for every white-gold or platinum alloy.

Keep the estimate tied to the exact revision. If a shoulder, gallery or ring size changes, the previous number may no longer describe the approved design. A screenshot of an old calculation should not remain the controlling price reference.

Separate metal weight from assembled weight

State whether stones, solder, findings and other supplied parts are included. Also identify whether the figure describes the model, an unfinished component or the finished article. Material removed during preparation means those stages should not be treated as interchangeable.

For example, a pendant body model and a completed pendant with its bail and stone are different weighing subjects. This is a scope distinction, not evidence that either calculation is wrong. Record the agreed subject alongside the value.

Agree how the final figure is confirmed

Ask when the physical piece will be weighed and how any price adjustment will be calculated. This belongs in the quotation, especially where material cost is based on actual rather than estimated weight. Avoid inventing a percentage allowance that the workshop has not agreed.

Use the manufacturing cost guide to keep material assumptions separate from development and bench labour. A weight estimate can inform a decision without pretending to calculate the whole commission.

Keep the estimate traceable

Retain the model reference, alloy assumption, included components and agreed weighing stage together. The next person reviewing the quotation can then understand the figure without reconstructing how it was produced.

Frequently asked questions

Can a CAD weight be guaranteed?

Only if the supplier has explicitly agreed a defined outcome and its conditions. A model estimate alone does not establish the final weight or the commercial treatment of a difference.

Should stone weight be included?

State whether you need metal mass or the weight of the assembled article. Keep stone and component assumptions visible so the figures can be compared fairly.

Related reading

• What Affects the Cost of Jewellery Manufacturing?
• Jewellery CAD Renders vs Production Files: Understanding the Difference
• Jewellery Manufacturing Tolerances: Agreeing What Is Acceptable

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