Abstract: According to one embodiment, a method of calibrating level sensors of at least two lithographic projection apparatus to correct machine to machine level sensor process dependency includes using a first lithographic projection apparatus to measure a first set of leveling data for a reference substrate and a second set of leveling data for a substrate processed according to a selected process, and using a second lithographic projection apparatus to measure a third set of leveling data for the reference substrate and a fourth set of leveling data for the processed substrate. The method also includes calculating, based on the first, second, third and fourth sets of leveling data, a set of level sensor parameters corresponding to machine to machine level sensor differences for the selected process, wherein the machine to machine level sensor differences are measured and stored as intrafield values.

Abstract: A method and an apparatus for folding paperlike material, such as documents, which may have different quality and length and are conveyed in assembled form or successively in a transport track, said paperlike material having a leading and a trailing edge and being provided with a fold at a location between its leading and its trailing edge by bending the leading edge and the contiguous portion of the material out of the transport track during conveying of the material until the trailing edge reaches a predetermined position and creating a sharp folding edge by bringing the edge to be folded between folding means by a folding blade moving substantially in the transport track.