What Is PVD Coating on Jewellery? A Doctor's Guide to Durability, Safety and Skin

You have probably seen "PVD coated" on a jewellery listing and wondered whether it means anything beyond a marketing term. It does. PVD is a real industrial process with measurable properties, but whether it makes a piece safe for your skin depends on something most brands never mention: the metal underneath.

How PVD coating works

Physical Vapour Deposition is a blanket term for several vacuum-based coating techniques, but the principle is the same across all of them. A source material, often a metal like titanium or zirconium, is vaporised inside a vacuum chamber at temperatures between 150 and 500 degrees Celsius. The vapour travels across the chamber and condenses onto the target object, forming a thin, dense film that bonds at the molecular level.2

When a reactive gas such as nitrogen is introduced during the process, the vaporised metal reacts with it mid-flight to form a compound. Titanium plus nitrogen produces titanium nitride (TiN), which has a characteristic gold colour. Zirconium plus nitrogen gives zirconium nitride (ZrN), a warmer gold. Chromium nitride (CrN) produces darker, gunmetal finishes. The colour is a property of the compound itself, not a dye or pigment.

The resulting film is typically 0.5 to 5 microns thick. For context, a human hair is roughly 70 microns wide. What PVD lacks in thickness it compensates for in hardness: titanium nitride measures around 2,000 to 2,500 HV on the Vickers scale, compared to about 100 to 200 HV for pure gold.3 This is why PVD-coated jewellery resists scratching far better than gold-plated pieces.

PVD coating vs gold plating: what actually differs

Gold plating and PVD coating both add a thin layer to a base metal, but the methods and results are quite different. Traditional gold plating uses an electrochemical bath to deposit real gold onto a surface. The layer is soft, thin (typically 0.05 to 0.5 microns), and wears through relatively quickly, especially on high-contact areas like clasps and ring bands.

PVD deposits a ceramic compound rather than a precious metal. The bond is mechanical and molecular rather than purely chemical, which makes it more resistant to peeling. The hardness difference is substantial: PVD TiN is roughly 10 to 20 times harder than electroplated gold.

The table reveals something important: for both gold plating and PVD, the answer to "is it safe for my skin?" is always "it depends on the base metal." The coating is temporary; the base metal is permanent.

The base metal problem: why PVD safety is not straightforward

Most PVD jewellery on the market uses 316L stainless steel as the base. This is sometimes described as "surgical steel," a term that sounds reassuring but is not regulated in the jewellery industry. 316L stainless steel contains between 10 and 14% nickel by weight.1 Nickel is the most common cause of allergic contact dermatitis, affecting an estimated 8 to 19% of the population in Europe.4

While the PVD coating is intact, it acts as a physical barrier between your skin and the nickel in the steel. The coating itself, if it is a nitride compound like TiN, is biocompatible and does not release nickel.5 The problem arises when the coating wears through.

PVD coatings are thin. Even at 5 microns, repeated friction from clothing, skin, and daily contact will eventually break through. Micro-scratches accumulate invisibly before you notice any colour change. Once the steel beneath is exposed, moisture from sweat or water can trigger nickel ion release from the base metal. For someone with nickel sensitivity, this means the piece that was fine for a year may suddenly cause a rash.

Is PVD coating biocompatible? What the research says

Titanium nitride, the most common PVD coating used for gold-tone jewellery, has been extensively studied for medical implant applications. A 2015 review in BioMed Research International examined TiN coatings on orthopaedic implants and found favourable biocompatibility and tribological (wear) properties across multiple studies.5 Separately, research on TiN-coated dental implant abutments reported that TiN reduces early bacterial colonisation and enhances soft tissue cell adhesion compared to uncoated titanium.6

A 2003 study published in the Journal of the European Ceramic Society tested TiN-coated metallic biomaterials for corrosion and biocompatibility, confirming that the coating provided a stable, corrosion-resistant surface.7

The evidence is clear that TiN itself is a safe material for skin contact. The clinical concern with PVD jewellery is not the coating, it is what happens when the coating is no longer there. In medical implants, TiN coatings are applied to titanium or cobalt-chromium alloys that are themselves biocompatible. In budget jewellery, TiN is applied to stainless steel, which is not.

PVD over stainless steel vs PVD over titanium

The base metal beneath a PVD coating fundamentally changes the safety profile of the finished piece. Here is why.

PVD vs anodised titanium: a closer comparison

Anodisation is sometimes confused with PVD because both can produce coloured finishes on titanium. The processes are fundamentally different.

PVD deposits a foreign material onto a surface. The coating and the base metal are two distinct substances bonded together. Anodisation, by contrast, modifies the surface of the metal itself through an electrochemical process. When titanium is anodised, an oxide layer grows from the metal's own surface. When the process involves nitrogen, a titanium nitride (TiN) layer forms that is chemically integrated with the base titanium.5

The practical difference matters. An anodised titanium surface cannot peel, chip, or delaminate in the way a PVD coating can, because it is not a separate layer sitting on top. It is the metal. If the surface is scratched, what is exposed is more titanium, not a different metal. There is no hidden reactive layer underneath.

For jewellery, this distinction is significant. PVD gives you a hard, attractive coating over a base metal that may or may not be skin-safe. Anodised titanium gives you a modified surface on a metal that is skin-safe all the way through. If you are choosing between the two specifically for sensitive skin, the base metal comparison is what should guide the decision.

When PVD is a good choice, and when it is not

PVD coating is not inherently bad. It is a well-established industrial process with genuine advantages over traditional plating. Here is where it makes sense.

How to check what is under the PVD

Brands are not always transparent about base metals. Here are practical ways to find out.

Look for specific alloy names. "316L stainless steel" or "surgical steel" both mean nickel is present. "Implant-grade titanium" or "ASTM F136" means it is not. Vague terms like "premium metal" or "high-quality alloy" usually indicate stainless steel.

Check for third-party testing. Brands that use nickel-free materials often provide certificates showing compliance with EN 1811 (the European standard for nickel release testing) or ASTM F136 (the specification for implant-grade titanium alloy).8 If a brand claims to be "nickel-free" but offers no testing data, treat the claim with caution.

Consider the price. PVD over stainless steel is significantly cheaper to produce than PVD over titanium. If the price seems too good for titanium, it is probably steel. For a deeper look at what different metal stamps and grades mean for your skin, our sterling silver guide covers the principles in detail.