A buyer orders 18k gold necklaces at $5 each. Three months later the customer photos show a green-brown base showing through at the bail. The supplier delivered 0.3 micron flash plating over brass, and the buyer wrote gold on the hangtag. Electroplating is the most misunderstood step in jewelry sourcing, and the one that drives the most warranty claims. This guide explains what plating is, how thick it needs to be, and what to write on your PO.
What electroplating actually is
Electroplating is an electrolytic process that deposits a thin layer of one metal onto another. The base piece, brass, copper, sterling silver, stainless steel or zinc alloy, hangs in a bath with a soluble salt of the plating metal. Current flows, and gold, rhodium, nickel, silver or copper ions plate onto the surface. The layer is measured in microns, where 1 micron equals 0.001 mm.
Plating does two jobs at once. It changes color (rose gold, black rhodium, two-tone) and it changes surface properties (tarnish resistance, hardness, shine). It is not a structural layer. Wear-through is not a defect; it is a timing question, and the timing depends almost entirely on micron thickness and base metal.
Micron thickness and what it means in wear
The industry bands that matter for sourcing:
- 0.05 to 0.5 micron flash plating. Cosmetic only. Wears through in weeks on contact points like bails, ear wire posts, ring shanks. Common on $2 fashion pieces.
- 0.5 to 1 micron commercial plating. Standard for plated brass and silver. Survives 3 to 12 months of gentle wear. Acceptable for occasional-wear pieces.
- 2 to 3 micron gold vermeil. Sterling silver base, gold plated to at least 2.5 microns under US and UK conventions. Lasts 1 to 3 years with reasonable care. The sweet spot for mid-market gifting.
- 5+ micron heavy plating. Built to survive daily wear for years. Used on high-end fashion pieces and custom commissions.
- PVD (physical vapor deposition). Not electroplating at all: a vacuum-deposited ceramic-metal layer, usually 0.5 to 2 microns but far denser. Wears 3 to 10 times longer than wet plating of the same thickness, especially in black and gunmetal finishes.
When a supplier says gold plated without a micron number, assume 0.3 to 0.5 microns. When they say vermeil, ask for the silver base proof and the micron reading. The legal definition of vermeil in the US requires sterling silver base and gold plating of at least 10 karat and 2.5 microns; anything thinner is just gold-plated silver.
Color, tarnish and nickel release
Plating changes color in ways that solid metal cannot. Rose gold plating uses a copper-rich gold bath. Black plating uses rhodium or ruthenium. Two-tone pieces are built by plating one area, masking it, and plating the other. The color is stable while the layer survives; when it wears through, the base color shows at the contact point, not uniformly across the piece.
Nickel is the hidden issue. Nickel sits under gold plating as a barrier layer in much commercial plating, and it releases through micro-abrasions onto skin. For EU sales, the REACH nickel directive limits nickel release on skin-contact items, and the ECHA guidance lists which fastener and jewelry components are covered. Specify nickel-free plating on the PO, not just in the marketing copy.
For the fineness marking rules that apply to silver-base plated pieces, the 16 CFR Part 23 rules set what you can stamp. A 925 stamp on a plated piece is fine if the base is sterling; a 14K stamp on a plated piece is not.
What to write on the PO
Three lines eliminate most plating disputes: base metal (brass, sterling 925, 316L stainless), plating metal and thickness (18k gold PVD, 1 micron), and nickel status (nickel-free, lead-free). Add a photo of a cross-section or a micrometer reading on the first sample. Reject any supplier who cannot give you a micron number.
If you are choosing between plating styles, read our black rhodium plating guide and the vermeil vs gold-filled comparison. Stores that sell plated pieces should hand customers our cleaning frequency guide, because soap and sweat are what burn through plating fastest. For base-metal tradeoffs, see sterling silver vs stainless steel.
Frequently asked questions
How thick should gold plating be to last?
For daily wear, spec 2.5 microns minimum on a sterling base, which is vermeil. For occasional wear, 1 micron on brass is acceptable. Below 0.5 micron, plan on replating within months.
What is the difference between PVD and electroplating?
PVD is a vacuum-deposited ceramic-metal coating, denser and harder than wet electroplating, and longer-wearing at the same micron thickness. It is the standard for black, gunmetal and matte finishes on stainless steel watches and rings.
Does plated jewelry turn skin green?
Thin plating over brass or copper can, once the layer wears through. Sterling silver base or stainless steel base avoids the green reaction almost entirely.
Can you replate plated jewelry?
Yes, at a jeweler. But replating costs $15 to $40 per piece, so it only makes economic sense on pieces with a base value above the replating cost.
Is gold filled the same as gold plated?
No. Gold filled has a solid gold layer mechanically bonded to a brass core, typically 5% by weight, and wears 10 to 30 times longer than plating. See the vermeil vs gold-filled comparison for details.
Source plating you can spec and defend. HOLYCOME supplies vermeil, PVD stainless and heavy-plated brass pieces with micron thickness on every spec sheet, nickel-free and REACH-compliant. Ask for a plating spec card and a sample batch for your QA lab.
