Pure Palladium And Palladium-Nickel: Two Approaches To White Finishing

Finishes represent the final step of the electroplating process, but also one of the most critical, because this is where aesthetic performance, resistance, and regulatory compliance come together. For white finishes in fashion accessories, this stage is mainly based on two solutions: pure palladium and palladium-nickel, with differences that go beyond colour and affect the entire system balance.

Historically, white finishing has been achieved using palladium-nickel alloys, because they ensure a bright colour and good tarnish resistance thanks to the presence of nickel, a very stable metal. From a technical standpoint, until recently this was also the only solution capable of achieving high thicknesses.

Alongside this solution, however, a significant evolution is emerging: pure palladium. “Today Legor is able to achieve significant thicknesses even with single-metal formulations,” explains Fulvio Sinisi, R&D & Technical Manager of the Surface Treatment division of the company, a leader in the production of metal alloys and electroplating solutions for the jewellery and fashion industries. “With PDSTARK-100 we can consistently achieve production thicknesses of up to 2 microns, maintaining a level of brightness aligned with palladium-nickel alloys, while most pure palladium solutions available on the market remain well below these thicknesses.”

The shift to pure palladium brings a direct advantage: the elimination of nickel. Even when present within legal limits and therefore classified as nickel-free, the metal remains in the system, with potential release risks and implications for both the end user and the operator managing the process.

This also brings operational simplification. Alloys require constant control of metal balance: any variation in bath composition can affect deposit performance and increase the risk of non-compliance. A single-metal system reduces these variables. “Managing a pure palladium bath is more straightforward: PDSTARK-100 requires only one replenisher additive, whereas an alloy involves a more complex management, with more parameters to control,” adds Sinisi.

Palladium-nickel remains the solution when working with high thicknesses. But even here there is room for optimisation: “PDSTARK-NI8020 allows deposits above 2 microns, reaching up to 5 or 6 microns in a single bath, as required for example in the eyewear sector. These are values that are difficult to achieve with standard market formulations, and verified in production,” Sinisi specifies.

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