Gold Plating Thickness in Microns: How Much Gold You Get
Two necklaces, both tagged gold, both under a hundred dollars. One has 0.4 microns of gold on it. The other has 5 microns, more than twelve times as much, and nothing on either tag tells you which is which. Here is how the measurement works, what Canadian law lets a seller print, and how to read a mark before you pay.
Two different ways to measure gold, and why they do not compare
Gold coverage gets measured two ways, and the two answer different questions.
Thickness, in microns. A micron is one thousandth of a millimetre. Electroplating deposits a gold film on a finished piece, and the depth of that film is what gets measured. This is how plated goods and vermeil are described.
Weight, as a fraction. Gold filled and rolled gold plate are made by pressure bonding a sheet of gold alloy to a base metal core, then rolling the two together. What gets measured is the share of the finished weight that is gold, so a 1/20 mark means 5 percent.
Lining the two up requires the piece's weight and surface area, which nobody has at the till. Treat them as separate scales, where a bigger number means more gold.
The three tiers of plating thickness
Plating thickness is not standardised for jewellery the way karat is, so the trade uses loose tiers.
Flash plating, under 0.5 microns. A colour coating, there to make a piece look gold on a shelf and in a photograph. On a ring it wears through in months. Assume this on anything sold under twenty dollars.
Standard gold plate, 1 to 3 microns. The common range for fashion jewellery from a real manufacturer. It survives gentle wear for a year or more, and it is where Canadian law starts permitting a printed thickness figure.
Heavy gold electroplate, 5 microns and above. Built to last, and the thickness Canada demands on a gold plated watch case.
What Canadian law actually requires
The Competition Bureau of Canada publishes the detailed marking requirements, backed by the Precious Metals Marking Act.
To carry a gold quality mark at all, an item must be between 9K and 24K. Nine karat is the Canadian floor for the word gold on a solid piece.
For gold plated goods the layer must be at least 10K, and the thickness may be marked only when it reaches at least 1 micrometre, written as a whole number followed by micron, micrometre, or the µ or µm symbol. Printing a thickness is optional. The rule governs when you are allowed to. Gold plated watch cases get the stricter rule: at least 5 micrometres on the outer surface of the case.
Gold filled needs a layer of at least 10K making up at least 1/20th of gross weight, with a tolerance: the gold has to weigh at least 90 percent of the required amount, or 80 percent if the item is engraved, brocaded or diamond faceted, since cutting the surface takes gold away.
Rolled gold plate covers the same construction with a 10K layer under that 1/20th share, marked with its own fraction, like 1/30 10K R.G.P. Vermeil requires a sterling silver base of at least .925 with gold plating of at least 10K.
| Category | Minimum karat of gold layer | Quantity requirement | Base metal | Example mark |
|---|---|---|---|---|
| Solid gold | 9K minimum, 24K maximum | Gold throughout | None | 14K |
| Gold plated | 10K | Thickness markable only at 1 micrometre or more | Any | 10K 3 micron |
| Gold plated watch case | 10K | 5 micrometres minimum on outer case surface | Any | 10K 5 micron |
| Gold filled | 10K | At least 1/20 of gross weight, 90% tolerance, 80% if engraved or faceted | Any | 1/20 10K G.F. |
| Rolled gold plate | 10K | Less than 1/20 of gross weight | Any | 1/30 10K R.G.P. |
| Vermeil | 10K | Thickness not fixed by the rule | Sterling silver, .925 minimum | Vermeil |
Running the numbers on a real piece
Fractions feel abstract until you convert them to grams. A gold filled bangle weighing 20 grams marked 1/20 10K G.F. carries 1 gram of 10K gold. The same 20 gram bangle marked 1/30 10K R.G.P. carries 0.67 grams: the mark changed by a few characters and the gold dropped by a third. A flash plated bangle of the same size carries a fraction of a tenth of a gram. All three sit in the same case and look identical under shop lighting.
How long plating lasts, and why the answer depends on where you wear it
Plating does not dissolve or expire. It abrades. Gold comes off when the surface rubs against something harder, so the life of a finish is thickness divided by contact. That makes wear location the deciding factor, more than the thickness number.
Rings take the most punishment. The palm side rubs against every object you pick up, the sides grind against neighbouring fingers, and the band drags across a knuckle twice a day. On our bench the first bare patches appear at the palm side of the shank and the inside edge where the knuckle passes.
Bracelets come second. They slide along a wrist, knock against desks and car doors, and the clasp takes concentrated handling.
Pendants last longest. A pendant swings against fabric and skin, and fabric is softer than gold. The chain wears faster, because links rub against each other constantly.
Earrings sit close behind. Studs barely move once they are in, so the post and back see the friction while the visible front stays intact.
This is why a pendant and a ring plated in the same bath on the same day end up years apart in appearance. Same gold. Different amount of rubbing.
What to ask before you buy
Ask what the base metal is. Sterling silver under the gold makes it vermeil, a piece with value of its own. Brass gives you a piece worth its plating.
Ask for the thickness in microns and the karat of the layer. A thick coat of 10K and a thin coat of 18K are different products, and a seller who knows neither number has told you something.
Ask what happens when it wears, since many plated pieces use a nickel underlayer that becomes exposed as the gold goes, covered in our guide to nickel allergy and hypoallergenic jewellery. For vermeil against gold filled against solid, see our earlier guide, and our guide to hallmarks and your rights explains what a stamp obliges a seller to honour.
Pendants from our cases
Pendants are where a plated or vermeil finish earns its keep, and where solid gold buys you something you hand down.
Key Takeaways
- Plating runs from under 0.5 microns on flash plating to 5 microns and above on heavy electroplate, a tenfold range sold under the same two words.
- Canada permits a printed thickness mark only at 1 micrometre or more, so a stamped figure guarantees a floor.
- Gold filled needs a 10K layer at 1/20th of gross weight or more. Rolled gold plate uses the same construction with less gold and its own fraction mark, like 1/30 10K R.G.P.
- Gold plated watch cases require at least 5 micrometres on the outer surface, the strictest thickness rule in the Canadian regulations.
- Wear location beats thickness: a pendant with 2 microns can outlast a ring with 5, because a ring rubs against hard surfaces all day and a pendant rubs against cloth.
Frequently Asked Questions
How thick is the gold on a typical gold plated piece?
There is no typical number, and that is the problem. Costume flash plating can sit under half a micron, thinner than kitchen cling film. Fashion plating runs 1 to 3 microns. Heavy electroplate runs 5 microns and up. The gap between thinnest and thickest is more than tenfold, and both ends get sold with the same two words on the tag. Canada gives you one handle to grab. The Competition Bureau permits a thickness mark only when the plating is at least 1 micrometre thick, written as a whole number followed by micron or micrometre. So a stamped number means at least 1 micron of gold. A tag that says gold plated and nothing else tells you the seller either did not measure it or chose not to print it.
What does 1/20 10K G.F. mean on a clasp?
It is a gold-filled mark, and it packs three facts into a few characters. The 10K is the karat of the gold layer. The 1/20 is the share of the item's total weight that layer accounts for, so one twentieth, which is 5 percent. G.F. is the abbreviation for gold filled. Canada's marking rules set both floors: the layer must be at least 10K, and the gold must make up at least 1/20th of the gross weight. There is a tolerance built in. The gold must weigh at least 90 percent of the required amount, dropping to 80 percent if the piece is engraved, brocaded or diamond faceted, because cutting into the surface removes gold. On a 20 gram gold-filled bangle, that 1/20 means about 1 gram of 10K gold bonded to the outside.
Is gold filled the same as gold plated?
They are made differently and measured differently. Plating is an electrical process that deposits a gold film on a finished piece, measured in microns of depth. Gold filled is a mechanical bond: a sheet of gold alloy is pressure bonded to a base metal core, then rolled and drawn into wire or sheet, so the result is measured as a fraction of the finished weight. Comparing the two directly takes arithmetic, since one counts depth and the other counts mass. A 1/20 gold-filled chain carries 5 percent of its weight in 10K gold, which on ordinary chain diameters works out far thicker than a 0.5 micron film. Canada requires gold filled to be at least 10K and at least 1/20 of gross weight, per the Competition Bureau.
What is rolled gold plate and why is it marked differently?
Rolled gold plate is made the same way as gold filled, by pressure bonding a gold sheet to a base metal and rolling the pair together, with one difference that matters: there is less gold in it. The Competition Bureau reserves gold filled for pieces where the gold layer is at least 10K and reaches 1/20th of gross weight. When the gold layer is still at least 10K but falls below that 1/20th share, the item is classed as rolled gold plate instead. The mark looks like 1/30 10K R.G.P., meaning a 10K layer making up one thirtieth of the weight, which is 3.3 percent. So a 1/30 R.G.P. piece carries two thirds the gold of a 1/20 G.F. piece of the same weight. Older watch cases and vintage chains carry these marks often.
How long does gold plating last on a ring?
A ring is the hardest place on the body for plating, because it takes friction from three directions: the palm side against everything you hold, the sides against neighbouring fingers, and the band over a knuckle twice a day. At our bench, flash plating under 1 micron on a daily ring shows base metal at the palm and knuckle edge inside a few months. Plating at 2 to 3 microns gets a year or two. Heavy electroplate at 5 microns and up holds several years without manual work. Those are shop observations, since real wear depends on your job, your skin chemistry and how often the ring comes off. If you want a gold ring that survives without replating, buy solid gold and skip the calculation entirely.
Why does a pendant outlast a ring with the same plating?
Contact. Plating wears off by abrasion, so the gold you lose tracks how often the surface rubs against something harder. A pendant hangs against fabric and skin, moves with your body rather than against objects, and has no knuckle to be dragged over. A ring touches hard surfaces most of the day. Same 2 microns on both, and the pendant looks new for years while the ring shows brass at the edges before its first birthday. Earrings sit further along the gentle end, with the post seeing the friction. This is why our honest advice runs the same way every time: spend the money on solid gold for rings, and plated or vermeil is a reasonable buy for pendants and earrings.
What is the minimum karat for something to be called gold in Canada?
Nine karat. The Competition Bureau sets 9K as the minimum quality for a gold quality mark and 24K as the maximum. That floor applies to solid gold. Plated goods sit under a separate, higher rule: the gold layer must be at least 10K, and the same 10K floor applies to gold filled, rolled gold plate and vermeil. So a karat too low to carry a plating mark can still be legal as a solid piece, which surprises people. The karat number tells you the purity of the gold in the layer. It says nothing about how much of that gold is present. A tag needs to answer both questions, purity and quantity, before you know what you are buying. Most tags answer only the first.
Do gold plated watch cases have their own rule?
They do, and it is the strictest thickness rule in the Canadian marking regulations. For a gold plated watch case, the Competition Bureau requires at least 5 micrometres of gold on the outer surface of the case. Under the general plating rule, 1 micrometre is merely the threshold where a thickness mark becomes permitted. The reasoning shows once you handle a watch: a case is strapped to a wrist that swings against desks, sleeves and doorframes all day, and the lugs and case edges take constant contact. Thin plating there wears through in months. If a seller cannot tell you a plated watch case's thickness, treat that as an answer. Our watch service page covers what we handle in the shop.
Can worn gold plating be redone?
Often yes, and the honest answer includes when it is not worth doing. Replating means stripping the old gold, cleaning and polishing the base metal underneath, then running the piece through the bath again. Polishing removes base metal too, so a piece survives only a limited number of cycles before details soften and edges round off. Cost is the other factor. Replating a chain or simple pendant is a modest job. Replating a ring that wears through again in a year is money you spend repeatedly. Our view: replate sentimental pieces and gentle-wear items, and for a ring you wear daily, put the same money toward solid 14K instead. We wrote about the durability differences between karats in our 14K and 18K comparison.
Sources
- Competition Bureau Canada: Detailed requirements for marking of precious metals
- Justice Laws Canada: Precious Metals Marking Act (R.S.C., 1985, c. P-19)
Data sourced September 2026. Legal requirements are quoted from the Competition Bureau's published marking requirements as they stood at that date. Wear patterns come from replating and repair work on our own bench, offered as observation rather than measurement.
Visit Vanhess
We are a family-run studio at 2929 Barnet Highway in Coquitlam, and we designed and made most of what sits in our cases. Bring in a piece you are unsure about and we will read the marks with you under magnification and tell you plainly what it is, including when the answer is that it carries no gold worth counting. We serve Coquitlam, Port Moody, Burnaby, New Westminster and Vancouver. Call +1 (604) 653-6449.
