Jewellery and watchmaking: selling one-off pieces online

One piece, one unit, one possible buyer

Many items exist as a single unit: a workshop creation, a setting built around one given stone, a watch from a batch the supplier will not repeat. Two visitors adding the same piece to their basket at the same moment create an oversell that no restock will ever fix. Availability therefore has to be reserved at add-to-basket, with an expiry after a few minutes, rather than at payment as the three main CMS platforms do by default.

Reservation with expiry changes several things at once: an abandoned basket must release the piece automatically, the shop front must explain why an item vanishes mid-journey, and the back office needs a way to force a release when a customer calls. It is short to write, but it touches the basket, the checkout and the scheduled tasks together.

What the data model has to carry

• Non-standard variants. Ring size with French, US and UK equivalences; chain length; metal (yellow gold, white gold, rose gold, silver); stone. Metal shifts the price so far that each combination needs its own price, not a base price with add-ons.
• Fineness and hallmark. In France the fineness hallmark is compulsory above certain weights, and the fineness itself — 750 parts per thousand for eighteen-carat gold, 925 for silver — is part of the description of the goods. These are structured, filterable, exportable attributes, not a line slipped into the description.
• Custom engraving. A piece engraved with a buyer’s name is clearly personalised goods, and falls outside the right of withdrawal under article L221-28 of the French consumer code. It must be flagged before confirmation, the engraved text kept on the order line, passed to the picking sheet, and the acceptance retained as proof.
• High value, negligible weight. No weight-based shipping grid survives: you need declared value, ad valorem insurance, signature on delivery, and sometimes a per-parcel ceiling that forces a shipment to be split.
• Photography and colour rendering. Return rates depend directly on how faithful the images are, which pushes towards very heavy files and high-definition zoom. Page weight then becomes a performance subject in its own right.