Alloying thin solid films can be difficult, especially when more than two substances are involved and a low deposition temperature is required. If additional demands like flexibility, stability and straightforward process control are stated, the number of deposition processes at hand is rather limited. Therefore, a co-sputtering technique involving the partial coverage of a target surface with metal foil has been studied in this work. Adopted from an earlier work, it was expanded to magnetron sputtering in order to better suit general, small-scale alloying of thin films and coatings. To evaluate the process, carbon coatings were alloyed by co-sputtering a carbon target with Al, Ta, W or Zr foil. The influence of metal type and degree of target coverage on film composition and properties was investigated. It is concluded that this co-sputtering approach can be used to alloy thin films and coatings in a very simple and straightforward manner, with excellent possibilities of controlling the amount of alloying elements. Coating deposition proved successful, yielding films with a wide compositional variety. The process temperature was 70 degreesC and stability during operation excellent. Depending on type and amount of metal added, the grown coatings ranged from amorphous to highly crystalline. Their mechanical properties were also shown to vary greatly with chemical composition. (C) 2004 Elsevier B.V. All rights reserved.