What GPSR changes
The EU General Product Safety Regulation applies to consumer products sold in the EU, jewelry included. It places responsibility on the economic operator placing the product on the market and requires identifiable contact details on the product or its packaging.
For a brand importing from a factory, that means the manufacturer's identity and an EU-based responsible person have to be reachable from the packaging, not only from a website footer.
What goes on packaging
Typical packaging fields are manufacturer name and address, EU responsible person name and address, a batch or model identifier, material and care information, and any warning required for the product.
Space is limited on jewelry cards, so plan the layout with the packaging proof rather than adding a sticker at the end.
A workflow with suppliers
Collect the data once: legal entity names, addresses, contact channel and model identifiers. Approve artwork with those fields, verify the printed result on a production sample, and keep the record with the shipment.
Because the requirement is about traceability, the same information should appear in the commercial invoice and packing list.