A thin film deposition system for depositing a material onto a web of substrate travelling in an in-track direction along a web transport path, comprising: a web guide system having a plurality of web guides defining a web transport path for the web of substrate, the web guide system including: an entrance portion an exit portion; and further comprising a moveable portion along the web transport path between the entrance portion and the exit portion, the moveable portion including: a first moveable-position web guide; and a second moveable-position web guide; wherein the web transport path directs the web of substrate through the entrance portion, then around the first moveable-position web guide, then around the second moveable-position web guide, then through the exit portion; a web transport control system that advances the web of substrate along the web transport path at a web advance velocity; a deposition head for depositing the material onto a surface of the web of substrate as the web of substrate moves past the deposition head, the deposition head being located in a fixed position adjacent to the web of substrate along the web transport path between the first moveable-position web guide and the second moveable-position web guide; and a motion actuator system that synchronously moves a position of the first and second moveable-position web guides (502, 503) such that they move forward and backward in a moveable portion motion direction according to a defined oscillating motion pattern while maintaining a constant distance between the first and second moveable-position web guides (502, 503), thereby causing a portion of the web of substrate adjacent to the deposition head to move forward and backward in an in-track direction; characterised in that the web of substrate enters and exits the first and second moveable-position web guides (502, 503) in directions that are substantially parallel to the moveable portion motion direction. a web guide system having a plurality of web guides defining a web transport path for the web of substrate, the web guide system including: an entrance portion an exit portion; and further comprising a moveable portion along the web transport path between the entrance portion and the exit portion, the moveable portion including: a first moveable-position web guide; and a second moveable-position web guide; wherein the web transport path directs the web of substrate through the entrance portion, then around the first moveable-position web guide, then around the second moveable-position web guide, then through the exit portion; an entrance portion an exit portion; and further comprising a moveable portion along the web transport path between the entrance portion and the exit portion, the moveable portion including: a first moveable-position web guide; and a second moveable-position web guide; a first moveable-position web guide; and a second moveable-position web guide; wherein the web transport path directs the web of substrate through the entrance portion, then around the first moveable-position web guide, then around the second moveable-position web guide, then through the exit portion; a web transport control system that advances the web of substrate along the web transport path at a web advance velocity; a deposition head for depositing the material onto a surface of the web of substrate as the web of substrate moves past the deposition head, the deposition head being located in a fixed position adjacent to the web of substrate along the web transport path between the first moveable-position web guide and the second moveable-position web guide; and a motion actuator system that synchronously moves a position of the first and second moveable-position web guides (502, 503) such that they move forward and backward in a moveable portion motion direction according to a defined oscillating motion pattern while maintaining a constant distance between the first and second moveable-position web guides (502, 503), thereby causing a portion of the web of substrate adjacent to the deposition head to move forward and backward in an in-track direction; characterised in that the web of substrate enters and exits the first and second moveable-position web guides (502, 503) in directions that are substantially parallel to the moveable portion motion direction.