X-ray masks are an expensive part of the x-ray lithographic technology. The overall mask making process can be simplified and the cost reduced by a judiciously applied replication process. It is desirable that the copy has negligible feature bias and minimal placement distortion. It should therefore be produced by a process that has the greatest possible latitude with respect to dose and gap. In this article, it is described how these conditions are met. The latitude requirement is met by engineering the exposure system so that the source has a prescribed amount of spatial incoherence. This technique is an extension of the zero magnification method used by Wells et al. [J. Vac. Sci. Technol. B 10, 3221 (1992)]. This approach is particularly well suited for synchrotron-based x-ray lithography.