Abstract: Assembly and method for depositing a thin film including: providing an expanding thermal plasma plume, including at least one chemical component to be deposited; designating a first and a second deposition zone within the plasma plume, such that the first and second deposition zones have a mutually different relative content of the chemical component; providing a substrate, and transporting said substrate through the plasma plume along a substrate transport path having a substrate transport path direction; and providing a mask that is at least partly disposed in the plasma plume and that shields a portion of the substrate transport path from being deposited on, wherein said shielded portion of the substrate transport path extends in the direction of the substrate transport path and bridges at least the first deposition zone, while it starts or terminates in the second deposition zone.