ZF 440 is a high-strength acidic black ruthenium electroplating solution designed to produce dark to glossy black finishes for decorative applications. It offers long bath life, is easy to maintain, and is primarily recommended for rack plating.
The wear resistance of the deposit ranges from good to excellent, depending on the desired depth of the black finish.
A thin gold underlayer is highly recommended. However, if palladium-nickel or palladium is used as the base layer, gold underplating is not required.
ZF 440 is ideal for a wide range of decorative applications including jewelry, bathroom fittings, eyewear frames, writing instruments, and automotive interiors.