RUTHUNA® 490 Black Ruthenium Electrolyte

Dark ruthenium coatings without strike gold plating

RUTHUNA® 490 Black is a neutral electrolyte for brightness retaining, dark grey to anthracite coatings. The black ruthenium electrolyte is easy to operate and has a good colour constancy.

RUTHUNA® 490 Black permits the direct plating of copper, nickel, brass or bronze. This means that strike gold plating or strike plating with palladium or palladium alloys is not necessary, which leads to enormous precious metal cost savings.

The black ruthenium electrolyte is suitable for decorative applications, above all in the clothing industry. It can be used for rack and barrel plating operations. Due to its high abrasion resistance, subsequent lacquering is not necessary, reducing the number of further process steps. Its positive features make themselves apparent even at a low ruthenium concentration of just 2 g/l.

Electrolyte characteristics

Electrolyte type


Metal content

2 (1.8 - 2.2) g/l Ru

pH value

7.0 (6.5 - 9.0) at 65 °C

Operating temperature

65 (60 - 70) °C

Current density range

1.0 (0.5 - 3.0) A/dm²

Plating speed

Approx. 0.02 μm/min at 1.0 A/dm²

Anode material

Pt/Ti or MMO (type PLATINODE® 167 or 177)

Coating characteristics


Black ruthenium


99 wt. % Ru

Colour of deposit

Grey to anthracite (black)




  • Neutral black ruthenium electrolyte
  • Simple bath maintenance
  • Dark grey to anthracite coatings
  • For decorative applications
  • High abrasion resistance
  • No lacquer finish is needed
  • Good colour constancy
  • Direct deposition on bronze or nickel possible
  • No intermediate layers of expensive palladium or gold necessary
  • Enormous precious metal cost savings
  • Suitable for rack and barrel


  • Accessories in the clothing industry
  • Baby clothing
  • Car interiors

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Questions about the product?

Markus Legeler

+49 7171 607 204

For inquiries and additional information
please contact

Umicore AG & Co. KG
Rodenbacher Chaussee 4
63457 Hanau-Wolfgang

Tel.: +49 (6181) 59 6005
Fax: +49 (6181) 59 2970

The information and statements contained herein are provided free of charge. They are believed to be accurate at the time of publication, but Umicore makes no warranty with respect thereto, including but not limited to any results to be obtained or the infringement of any proprietary rights. Use or application of such information or statements is at the user´s sole discretion, without any liability on the part of Umicore. Nothing herein shall be construed as a license or recommendation for use, which infringes upon any proprietary rights. All sales are subject to Umicore´s General Conditions of Sale and Delivery.