How to approve jewellery plating and wear trials
Approve a defined coating build, measured thickness evidence and physical colour boundaries, then agree rubbing and perspiration trials with written failure criteria. Keep chemical restriction checks separate from appearance approval. Cambridge China Bridge can coordinate samples and factory checks through its staff in China.
Define the finish you are approving
Record the base metal, each plating layer, final colour and any protective coating against the product and finish code. Identify exposed edges, recesses, skin-contact surfaces and moving parts. The jewellery findings guide covers component specifications; this approval should add measurable finish and wear criteria.
Ask for samples made using the proposed production process, including polishing and protective coating. Label retained samples with their finish and batch identity. Agree that a change to the base metal, plating layers, coating or plating subcontractor triggers review before production continues.
Ask for thickness evidence by location
Agree a minimum thickness for the relevant plating layer at named measurement locations, rather than accepting a nominal figure for the whole piece. Ask the factory or laboratory to propose a suitable measurement method for the material, layer structure and shape. Require the report to identify the layer measured, units, method, sample identity and individual readings.
Mark measurement points on a drawing or photograph, including vulnerable edges and contact areas where measurement is feasible. Ask how inaccessible areas will be assessed and how the instrument distinguishes neighbouring layers. A flat witness coupon can help monitor the process, but should not replace evidence from the actual article without an agreed technical justification. Use the test report coverage guide to check the report matches your order.
Set physical colour boundaries
Keep an approved target sample and labelled boundary samples showing the lightest, darkest or most differently toned finishes you will accept. Include gloss, texture, patchiness and the appearance of recessed areas. Compare pieces together under agreed lighting, against the same background and at the same viewing angle. Photographs are useful records but should not be the sole colour standard.
Check assembled jewellery as well as loose components: a clasp, chain and pendant can each look acceptable alone yet mismatch together. Write down whether colour variation within a piece, between paired pieces and across a batch is acceptable. Keep an untested control sample for later comparisons.
Agree rubbing and perspiration trials
Write the trial procedure before testing: rubbing material, applied load, movement, repetitions and inspection points; for artificial perspiration, specify the solution, temperature, exposure duration, rinsing and drying procedure. Ask a laboratory to propose reproducible conditions suited to the intended use. Include chain links, clasps and edges that rub during wear. The durability testing guide helps frame the wider use conditions.
Agree failure criteria for exposed base metal, peeling, blistering, staining, loss of gloss and colour moving beyond the approved boundaries. Record results after rubbing, after perspiration exposure and after any agreed combined sequence, using identified samples and the retained control. Add a supervised wearing trial with a use diary only after chemical checks are satisfactory. Do not convert an accelerated trial into a lifespan claim without supporting evidence.
Release appearance and chemistry separately
REACH restrictions can limit, ban or set conditions on substances. Keep a separate chemical test scope covering applicable restrictions for the destination and article. For Great Britain jewellery, the existing UK REACH guide and findings guide explain cadmium, lead and nickel release checks. A good-looking finish, a thickness reading or a successful rubbing trial does not establish chemical compliance.
Ask the laboratory whether the coating and skin-contact use call for wear or corrosion preparation before nickel release testing. Match chemical reports to the base metal, plating build and tested components. Release the batch only when appearance, thickness, wear results and applicable chemical evidence have each been accepted. Record who approved each result, retain production samples and hold affected goods if evidence is missing or the finish has changed.
Frequently asked questions
What plating thickness should I specify for jewellery?
Agree it for the actual layer, article and intended use with the factory and laboratory. Specify minimum readings at named locations and confirm performance through trials; a nominal thickness alone is insufficient.
Can I approve jewellery colour from photographs?
Use physical target and boundary samples under agreed lighting. Photographs support the record, but camera settings and screens can hide differences in tone, gloss and matching components.
Does a sweat test prove jewellery is compliant?
No. An appearance trial records finish behaviour under its stated conditions. Obtain separate evidence for applicable chemical restrictions, including nickel release where relevant.
What should I do if plating fails a wear trial?
Hold approval, identify the failed locations and ask for a documented process correction. Repeat the affected trials on revised samples and review whether chemical reports still cover the changed finish.