The disclosure relate generally to structures, forms, and monoliths, and methods of preparing the same. This disclosure can produce uniform structured passageways or channels of active material, including adsorbent or catalyst, by imprinting or molding features into a paste on a support that can be subsequently assembled into a gas or liquid treating structure, i.e. a monolith. The paste, which can include an active material, binder, and other potential additives, can be applied to the support or pushed through a support (as in a mesh) as a thin film. The paste can be imprinted, stamped, shaped or otherwise handled to give features of desired height, shape, width, and positioning. When stacked or rolled, the features of one layer contact a subsequent layer, which seal to form passageways. The resulting structure can have high cell-density (>1000 cells per square inch) and a large volume fraction of active material.