Methods of combining catalytic plates into an assembly of a non-monolithic structure, such as a catalyst substrate or filter assembly, of an exhaust aftertreatment system. A plurality of plates may be disposed within a housing in an arrangement that may define a catalytically active volume of a substrate. Each of the plurality of plates may be single-curved or multiple-curved and/or may be represented by three-dimensional nestable structures. The arrangement of plates may be configured such that the flow is axial, radial, or represented by a hybrid, multi-segment intake path. The plurality of plates may be arranged such that they are configured to receive targeted amounts of coating agent, which may differ among the plates.