“Black” is three different coatings.

Black is the most requested colour in stainless steel jewelry and the least specified. Because PVD colour is set by the gas chemistry inside the chamber, several coating families can all be described as black, and they land at visibly different points between grey and near-black. A buyer who orders black PVD without naming the family is letting the factory choose the shade, the durability and the price.

Three routes to black

DLC (diamond-like carbon). A carbon-based coating deposited from a hydrocarbon or graphite source. It reads as a deep, neutral grey-black with no colour cast, and it is the hardest of the common jewelry coatings, with figures in the range of 2,000–3,000 HV commonly quoted. On high-contact pieces such as rings and bangles it is the benchmark for wear.

TiCN (titanium carbonitride). A titanium-based coating with carbon and nitrogen in the matrix. Its colour is a blue-black, sometimes read as gunmetal under bright light. Hardness is typically quoted above 2,000 HV, and its cost sits below DLC.

Dark titanium and multi-layer stacks. A titanium nitride family coating tuned dark, or a stack of layers ending in a dark topcoat. These read as softer charcoal, sometimes with a slight violet or brown cast. They are the least expensive route and the most variable in shade.

Each is a genuine PVD process. None is paint, oxide or lacquer, and none should be confused with the black oxide conversion treatments used elsewhere in metalwork, which sit on the surface rather than in it and wear through far sooner.

How the three compare

The families differ on every axis a buyer cares about, and the table below is the summary to work from.

The thickness figures are targets, not promises. Thin edges and deep recesses coat thinner than flat faces — a pocket 2 mm deep can receive a fraction of the face thickness — and the achievable range depends on part geometry and rack position.

Why black is less forgiving

Black tolerates less process drift than gold. The eye discriminates small differences in a neutral colour more sharply than in a saturated one, and a batch that drifts towards grey or brown is rejected by customers who would never notice a similar drift in a gold tone.

Three consequences follow. The colour reference must be physical, because photographs of dark neutrals shift with screen, lighting and compression, so a coated sample piece approved and retained as the golden sample is the only usable standard. Chamber-to-chamber variation is real, and a factory running several chambers holds colour tighter within one than across several, so a large single-SKU run should be coated in as few chambers as practical. And the substrate finish shows through: PVD replicates the surface beneath it, so a mirror-polished substrate reads as a deep, even black while a brushed one reads as grey.

How black wears

All of these coatings wear, and each family shows it differently. On DLC, wear appears first as a softening of the black towards grey on high points, as the thinned coating lets the steel's reflectance mix in. On TiCN and dark titanium stacks, the cast can shift before any base metal shows. On a ring the wear concentrates on the sides that meet tables and doorframes; on a bangle, on the clasp and the outer face.

Product copy should reflect this: describe black as a durable coating rather than a permanent colour, and set care expectations — the subject of our guide to colour fading — at the point of sale rather than in the returns queue. Corrosion behaviour is a separate question from wear, and salt spray ranking to ASTM B117 or the ISO 9227 cycle says little about how the shade holds up under abrasion.

Specifying black on a purchase order

A purchase order that survives the run states four things:

1. The coating family. DLC or TiCN, not black PVD.
2. The target thickness. Typically 0.5–1.5 µm for jewelry parts, stated as a range.
3. The substrate finish. Mirror, brushed or matte, because it decides the perceived shade.
4. The colour reference. An approved physical sample, retained by both sides.

Acceptance follows the same logic: coat sample parts, grade the shade against the reference under two light sources, and run a wear check on a contact surface. Because the coating is thin, buyers also ask what the substrate contributes underneath; nickel release from the finished piece is governed by EN 1811 testing rather than by the coating, and the FTC's Jewelry Guides require black-coated steel to be described as coated, not as a black metal. The shades this matters most on are the matte, high-contact pieces in men's jewelry and the black band styles that dominate our rings category; our guide to PVD colour matching covers the approval process in detail. To have the family, thickness and reference written into a quotation before sampling, start at the RFQ page.