Today, for stainless steel jewelry there is no reason to limit the color choice to the natural steel color. for steel jewelry PVD plating is my option of choice.
If you follow the steel jewelry industry for few years, you have had heard the terms coating, plating PVD, IP, IPG and “electroplating” many times.
Understanding the plating or coating methods and choosing the right one can be the difference between a failed to successful product. In addition to a big different in price and quality.
My aim in the following posts is to describe the main methods used in the steel jewelry industry using as less as possible technical terms.
I hope the information will serve you during your purchasing process in China.
For those who don’t have time and need quick answers.
- What is PVD?
PVD is 2 thin layers applied to the surface.
- What the different from IP to IPG to PVD?
In general no differences other than the applying method.
- Why not to use electroplating?
The colors are not stable and it’s not durable as PVD plating.
- Is there a price different?
Yes, PVD plating way more expensive.
- How durable is PVD plating?
in normal use, the plating won’t change for few years if done correctly.
- How to test PVD plating?
With X-ray machine for the thickness and ISO sweat test for the durability.
- what is the differences between glossy and satin PVD finishes?
There are no differences, the surface finish is according to the jewel polish.
The 4 coating and plating techniques mainly used in the jewelry industry.
- PVD (Physical vapor deposition) also refer by china suppliers as IP or IPG.
- Chemical also known as electroplating.
- Dip-coating, mainly use for silver and gold.
PVD plating (Physical vapor deposition) .
Vacuum deposition is a family of processes used to deposit layers atom by atom in vacuum chamber on a solid surface. The layers may be as thin as one atom to millimeters thick. There may be multiple layers of different materials. A thickness of 0.25 to 0.7micron is generally called a thin film and very common in the jewelry and watch industries. The majority of steel jewelry use 0.20 to 0.28 micron plating. It is very rear to find steel jewelry with 0.7micron plating (some top brands use 0.35-0.5 micron) as the changed in price is not proportional to the thickness different.
The 5 Main PVD plating (vacuum deposition) methods
- Cathodic Arc Deposition.
- Electron beam physical vapor deposition.
- Evaporation deposition (mainly used for jewelry and watches).
- Pulsed laser deposition Sputter deposition
8 most popular PVD plating colors for stainless steel jewelry.
- Gold, 14K, 18K, 24K color variations.
- Rose gold (pink gold)
- Dark grey.
All these colors are available in a polished, satin or brush finish according to the product surface polish.
PVD Evaporation deposition in simple terms.
The jewelry or parts to be coated are first cleaned. Then, a first layer of Tin (tn) is vaporized in a vacuum chamber and use as a “base”.
For gold and rose gold finish real gold (14K or 18K) is evaporated and deposited on the part under high temperatures or via ion bombardment as a 2nd layer. The shade of the gold is according to the gold content.
Color pigments or gas in other cases together with the Tin layer are used to achieve other colors during the first layer process (without the use of gold as 2nd layer).
Depending on the substrate material the process temperature can be controlled from 100 degree Celsius to 280 degree Celsius.
Depend on the plating thickness, the manufacturing method and the reaction with the body acid. PVD will last from 10 months to few years. It’s a good place to mention that Rose gold color slightly change its color to yellow gold during the time the same as real rose gold or white gold jewelry (the copper in the rose gold oxidized) .
PVD plating on jewelry is not a scratch proof or lifetime finish although it is last longer than other plating in similar thickness (Zirconium Nitride (ZrN) is used for application required hard finish)
Igh quality PVD are more durable than other plating methods.
The PVD price is relatively more expensive compare to other plating methods like Chemical, electroplating, or spraying but still lower than precious metal dip coating thanks to the thin film layer used.