The first article is "Transient and Steady-State DC Behavior of Oil-Impregnated Pressboard," by Fabian Schober, Stephan Harrer, and Andreas Kuchler of the University of Applied Sciences, Schweinfurt, Germany; Frank Berger of the Technische Universitat Ilmenau, Germany; and Wolfgang Exner and Christoph Krause of Weidmann Electrical Technology AG, Rapperswil, Switzerland. The article investigates the influence of pressboard density and oil conductivity on the conductivity of oil-impregnated pressboard, and both are shown to be important for achieving a desired conductivity of oil-impregnated pressboard for HVDC applications. Two pressboard types, low and high density, and two types of mineral oils, low conductive and high conductive, were used in the investigation. Both pressboard types exhibited similar apparent conductivities when impregnated with low-conductive oil, but when impregnated with high-conductive oil, an apparent conductivity 2.8 times higher was observed as a consequence of the larger oil volume. Yet, the numeric assessment of oil-impregnated pressboard conductivity by simple linear superposition of pressboard conductivity and oil conductivity does not provide the measured apparent conductivity. In addition, the influence of oil conductivity on the apparent oil-impregnated pressboard conductivity was evaluated. Pressboard impregnated with four types of mineral oil, spanning an apparent conductivity of 2.5 orders of magnitude, was found to be only in an apparent conductivity range of oil-impregnated pressboard of only 0.5 orders of magnitude. As an explanation for the observed phenomenon, it appears that new and modified charge transport paths in the oil volume altered the transport paths along pressboard fibers. Conduction processes therefore interact with each other, and this interaction opens a new and interesting field of further research. Selecting a suitable pressboard density and the right choice of mineral oil can be used to achieve the desired conductivity for the oil-pressboard insulation system, which may be an option for the optimization of HVDC insulation systems.