Jewellery plating hue and engraving depth
Whether plating holds one colour under two lights and whether engraving cuts deep enough to survive wear.
The reading sequence
4 steps, starting at surface and finish and running to check the contact points for plating wear. Evidence on this point is read at E1, and 2 of the 4 steps carries a condition that ends the assessment outright.
Shoot the same face under two lights
Get one photo under warm indoor light and one in indirect daylight, so a hue shift can be attributed to the light or to the plating.
Evidence: E1 — two photos of the same face of the piece, one indoors and one in open shade, each with a sheet of white paper in frame
- Both photos carry the same white paper reference, so the two can be compared.
- The piece is the same way up in both photos, showing the same face.
- Only one lighting condition is supplied.
- The white paper is in one photo but not the other, so there is no reference tone to compare against.
- The photos are colour-adjusted or filtered, so the plating hue cannot be read at all.
- The surface is angled so that it reflects the light source directly in both photos.
Compare the hue against the paper reference
Decide whether the plating reads as one colour under both lights, or shifts toward yellow or pink in daylight.
Evidence: E1 — the two step 1 photos read side by side, with the white paper in each used as the neutral reference
- The plating reads in the same colour family in both photos.
- Highlights and shadows on the piece stay the same hue rather than one turning warm and the other cool.
- A slight warm shift in daylight that keeps the plating inside the same colour family.
- A face that reads differently on a phone screen while matching the paper reference in both photos.
- The plating shifts from one metal colour to another between the two light sources.
- The colour changes across a single face, so the layer is thinner at one end of it.
Read the engraving in raking light
Judge the depth of the engraving and whether the letter edges are clean, using light across the surface rather than down onto it.
Evidence: E1 — a macro photo of the engraving with the light at about 15 degrees to the surface, plus one taken straight on
- Each letter carries a shadow along one wall for its whole length, placing the cut below the surface.
- Letter edges are straight, with no metal pushed up along either side.
- A shallow cut that shows a shadow along part of a letter but not the whole stroke.
- Slight rounding at the ends of a stroke, with the rest of the letter clean.
- Letters cast no shadow under raking light, so the mark sits on the surface rather than in it.
- Metal is pushed up along the letter edges, leaving a raised lip that will catch on cloth.
Check the contact points for plating wear
Find whether the plating is already worn at the points that rub against each other, which predicts where it fails first.
Evidence: E1 — macro photos of the clasp, the ring joint and the inner face of the band, each lit from the side
- Plating is unbroken at the clasp and at the ring joint.
- The inner face of the band carries no polishing marks through the plating.
- A faint lighter patch at the clasp where the layer is thinner but not open.
- Tool marks under the plating that show at one angle only.
- Base metal shows through the plating at a point that rubs.
- Plating has lifted along an edge and reads as a visible step.
Why the thresholds sit where they do
Plating is a layer measured in fractions of a micron, so the colour a camera records depends on the light source and on what the piece is sitting next to. Two light sources are required because a warm indoor lamp flatters a gold tone and hides a thin layer, while open shade exposes the base colour underneath it. Raking light is the only way to read engraving depth from a photograph: lit straight on, a shallow surface mark and a deep cut produce nearly the same image, and the shadow along one wall of a letter is the feature that separates them. The 15 degree angle was chosen because it was the steepest angle at which the same engraving still read clearly in repeated test photos. Contact-point wear is placed last because it is the finding that decides the outcome, and a piece already worn at the clasp wears faster once it is worn daily.
Common misreads
2 pairs recorded for this point. Each runs in both directions: 1 finding that looks worse than it is, and 1 that looks better.
- looks like Return actually Pass
A gold ring that reads pale and greenish in a daylight photo. Open shade is a blue light source, and every yellow metal shifts under it. The paper reference in the same frame shows whether the metal or the light moved.
- looks like Pass actually Return
Deep-looking engraving in a straight-on photo taken under a single lamp. A hard light from one side casts a shadow into a surface mark as readily as into a cut, so a mark sitting on the surface cannot be told apart from one cut below it.
Check this point against what you were sent
Insufficient evidence
Nothing decided on jewelry plating and engraving yet: 0 of 4 steps have been read.
0 of 4 steps judged
| Step | Reading | Evidence | Stop met |
|---|---|---|---|
| 1. Shoot the same face under two lightsneeds E1 | — | ||
| 2. Compare the hue against the paper referenceneeds E1 | The plating shifts from one metal colour to another between the two light sources. The layer is too thin to hold its colour, and it will wear through at the contact points first. | ||
| 3. Read the engraving in raking lightneeds E1 | — | ||
| 4. Check the contact points for plating wearneeds E1 | Base metal shows through at a point that rubs. Every closure widens that patch, so the finish is already past the stage where careful wearing protects it. |
Sources and checks
- Public community thread — Plating threads where the same piece was judged differently under two light sourcesn=48
- Editor analysis — 15 degree raking angle chosen from repeated test photos of one engravingno sample
Last checked · next review due · status current.
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