An accessories buyer running a $25 to $45 earring wall asked us which base metal to spec for a fall drop: solid copper, or brass under a gold flash. The answer changed the plating budget and the return rate. Copper and brass look warm next to each other on a tray, but they are different products in hand, in skin reaction, and in the wholesale cost ledger.
What each alloy actually is
Copper is the pure metal. Jewelry copper runs from 90% to 99% Cu, often with a touch of zinc or tin for stiffness. It is soft, it oxidizes to a dark patina, and it transfers its color to skin as a green or blue mark. Brass is copper plus zinc, typically 60% to 90% copper with the balance zinc. Adding zinc raises tensile strength and casts the metal into bright, dimensionally stable shapes at lower unit cost. The tradeoff: more zinc means more brittleness in thin wire and more risk of dezincification when the piece sits in a damp display case. The composition background is covered on the copper reference, and the naming conventions jewelers extend to base-metal equivalents follow the fineness framework behind ISO 9202 precious alloy fineness.
Skin reaction and the nickel rule
The number-one complaint on a base-metal earring wall is the green earlobe. That is not nickel allergy; it is copper salts reacting with sweat. It is worse on copper than on brass, because brass has less free copper at the surface once plated. Nickel allergy is a separate and more regulated problem: the EU Nickel Directive limits nickel release on articles intended for direct and prolonged skin contact to 0.5 micrograms per square centimeter per week, and on ear piercings to 0.2 micrograms. A brass earring post that is not properly plated can drift over that limit within a season of skin contact. If you export into the EU, ask your foundry for the nickel-release test report, not just the alloy spec sheet. Compare the hypoallergenic end of the market in titanium-steel versus sterling silver for sensitive ears.
Unit cost and plating math
At foundry level, copper sheet and wire usually costs 15% to 30% more than brass for the same cross-section, but brass machining and stamping are faster because the alloy cuts cleaner. Net landed unit cost for a cast stud is often within 5% either way, so the decision is rarely driven by the metal price alone. It is driven by plating. A copper base under 0.5 micron gold vermeil needs a nickel barrier to stop copper bleed-through; without that barrier the gold flash shows a rose tint within weeks. Brass takes a thinner flash because the zinc barrier already slows diffusion. If your product shot promises "warm copper tone," ship copper; if it promises "gold-tone earring," ship brass and plate.
Which alloy for which program
Spec copper for: patina bracelets, fold-formed cuffs, and artisan lines where the buyer expects the metal to age. Spec brass for: stamped charm drops, hoop earrings, and anything that needs a bright plated finish at a $12 to $28 wholesale band. Keep the two programs on different shelves so a customer does not return a copper cuff thinking it tarnished. Tie the choice to the care instructions in jewelry storage that avoids tarnish, and review the plating wear question in electroplating color and wear before you commit a seasonal quantity. Compare against the precious end of the alloy ladder in rose gold versus copper alloy wear.
Does copper jewelry turn skin green permanently?
The green mark washes off with soap. It is copper salts, not staining, and it fades within a day of removing the piece.
Is brass cheaper than copper jewelry?
Per finished unit, brass usually lands within 5% of copper after faster casting and less plating failure, even though raw brass is cheaper than raw copper.
Do I need a nickel test report for brass earrings?
Yes if you sell into the EU. Ask the factory for nickel-release measured against the 0.2 microgram per week piercing limit, and keep the report on file.
Which metal polishes to a brighter gold finish?
Brass polishes brighter and holds a gold flash longer. Copper reads more rose and will patina even under plating if the barrier layer fails.
How to talk about the alloy on the product page
Do not label a brass earring "solid copper" and do not label a copper cuff "brass." The FTC guides treat alloy descriptions as material facts, and a customer who buys a brass hoop expecting a patina copper piece will return it when the surface stays bright. The honest copy is: base metal brass with 0.5 micron gold flash, nickel-barrier plated. Add the micron thickness, the plating type, and the expected wear window (typically 6 to 12 months for a daily-wear earring under 0.5 micron flash). That level of detail drops return rates and sets the expectation that the plating is a finish, not the metal itself. It also gives the customer a reason to come back for a re-plating or a replacement rather than to post a disappointed review.
Need a base-metal program that plates clean and reorders on time? HOLYCOME supplies copper and brass castings and stampings with nickel-release test reports and low MOQ for first-time buyers. Read our first-order checklist or ask for a metal sample card for your next drop.
Frequently Asked Questions
How do I verify a factory before placing a bulk order?
Request a production video, business license, export records and a paid sample run. A factory that accepts a 50-piece test order is usually a real manufacturer.
What payment terms do you offer?
30% T/T deposit with the balance against the bill of lading. This protects both sides on first orders and can move to net terms after a track record.
What is your normal reject rate?
3–5% under 10x loupe inspection for cast and set pieces. Defective units are replaced free in the next shipment.
Where is the factory located?
Wuzhou, Guangxi, China—the core lab-grown and moissanite manufacturing cluster. Shipments go via Guangzhou or Shenzhen ports.
