The procedure following the washcoating of three different Ni catalyst systems (MgO, Al2O3, and CeO2/Al2O3 supported) on pretreated Fecralloy (R) microchanneled foils under controlled milling times and viscosities of the slurries is described. The activity of the prepared coatings is also presented. Four different series of coated foils were prepared: one per each catalyst system, keeping constant the average particle size on 5 mu m, and one extra series to study the effect of reducing the average particle size of the MgO-supported catalyst system to 3 mu m. For each coating, scanning electron microscopy pictures were taken and specific surface areas and average densities of the catalyst layers were estimated. Finally, each series of coated foils was stacked and tested in a microreactor for the methane steam reforming (MSR) reaction under different conditions.