Many composers have in their catalogue a series of pieces with either the same title but a different number, or a common theme that links them. Michel Lysight adopted the latter option for his Metal Series, with the common characteristic that each is written for a duo.

The series opened with Titanium for saxophone and bass clarinet. This was followed by Tin for two saxophones, Palladium for two flutes, Cobalt for piano four hands and Platinum for clarinet and cello.