A lab report proves that the pieces sent to the lab passed. It says nothing about pieces made later from a different batch of metal or plated in a different tank. To make sure your shipment matches the report, fix the materials in writing, draw test samples from the finished bulk lot, and link every report to a lot number.
This matters because many imitation jewellery workshops buy metal, findings and plating chemicals in small lots from different suppliers. Each change is a chance for lead, cadmium or nickel to slip back in.
Lock the bill of materials
Ask the maker to list the base metal, the source of findings such as clasps and earring posts, the solder, the plating layers in order and their thickness, and any coating. Put this list in the purchase order and say that no change is allowed without your written approval.
If a supplier must change, for example because a metal dealer is out of stock, the new material should be tested before production continues.
Test from the bulk, not only the sample
- Pre-production: test the approved sample to confirm the design and materials can pass.
- Bulk: once production is finished and plated, draw pieces at random from the lot and test again.
- Seal the drawn pieces in a bag signed by your inspector so the workshop cannot swap them.
- Screen extra pieces on site with an XRF analyser if available, then send a smaller set to the lab for the full test.
Keep the paper trail
Give each production lot a number and print it on the packing list and carton marks. Each test report should name the style, the lot number and the date the samples were drawn. If a customer or an authority asks later, you can show which report covers which goods.
Keep a sealed counter-sample from the approved lot as well. It is the reference for any dispute about finish or plating colour, and it can be retested if a question comes up. See how to make sure your order matches the approved sample.
Plating batches deserve special attention. A workshop may plate one order across several days or in several tanks, and the underlayer and thickness can drift between them. Ask the maker to record which tank and date each lot was plated, and draw your test pieces from more than one batch where an order is large.
What this means for a buyer
Most compliance failures happen between the sample and the shipment, so that is where your checks belong. Creston & Co works for buyers only, for a fixed fee agreed in writing. We draw and seal test samples from the bulk lot in Rajkot, send them to NABL-accredited labs and supervise packing. Start with a free sourcing review.