A new class of composite materials is prepared using traditional high speed and low cost paper making equipment and techniques. In this process, μm diameter metal fibers in a variety of compositions and alloys are slurried in an aqueous suspension with cellulose fibers and other selected particulates and/or fibers. The resulting mixture is then cast into a preform sheet using a wetlay process and dried to create a sheet or roll of preform material. Subsequent sintering of the preform at elevated temperatures (ca. 1000 o C) removes the cellulosic binder/pore former and entraps the selected particulates/fibers within a sinter-locked network of conductive metal fibers. Unique physical properties are obtained in terms of: void volume, thermal/electrical conductivity, porosity, surface area, permeability, particle size, layer thickness, etc. To a first approximation these composites possess averaged physical properties over heretofore unavailable regions located between those of the entrapped component and those of the high void volume sintered metal carrier. For chemical processing applications the high void volume of the metallic binder/carrier (i.e. 20-99%) facilitates intralayer heat and mass transport while the ability to trap very small particulates (using the novel pore size-void volume relationship of microfibrous carriers) greatly reduces intraparticle heat and mass transport. A description of the unique and fundamental structure-property relationships and behaviors of these materials will be presented and contrasted with those of the more traditional engineering approaches and practices using fused particulates and pasted-carriers. Opportunities for significant steady-state volumetric processing improvements result when one must balance the competing demands of chemical kinetics (e.g. at the entrapped particulates) with those of the required transport processes (i.e. via the interparticle and intralayer voidage). Examples of beneficial processing applications and opportunities will be discussed in: (a) heat transfer materials, (b) catalysts and sorbents, (c) electrochemical processing and (d) filtration.