& #x00A9; 2016, Springer International Publishing Switzerland. We present a free-form medium of curation for digital arts catalogues, which connects an infinite zoomable canvas, sketching, and spatial arrangement of rich catalogue elements. We draw on an architectural theory that integrally joins the properties of building materials, construction techniques, and sites to develop a tectonic theory of media of digital curation. The theory addresses media of curation on two levels: the materials of elements that can be collected and the medium of assemblage, which prescribes how those elements can be joined together in a spatial matrix. The elements of prior digital arts catalogues are joined together in linear lists or grids. These assemblages do not scale well, making them agonizing to wade through when collections are large. Assemblage in our new, free-form medium supports curating across multiple scales, easing demands on visual attention, while opening conceptual horizons. We created an artifact, The Digital Curated, as an example of a digital arts catalogue represented in our new medium.