This special issue, “Making Animal Materials in Time,” delves into the history of animal materials used in craft and scientific endeavors since the eighteenth century. We regard animal materials as dynamic elements with particular properties granted context-specific and culturally fluid meanings by those who work with them—often to the point of dissolving their original animal materiality. Focusing on this multi-dynamic at the intersection of history of science and the anthropology of techniques permits a reformulation of the concept of affordance, as material affordances, to create the theoretical capacity for a discussion of the diverse processes of rendering animal bodies into new substances, materials, and things. Six case studies illustrate how human historical actors distinguished animal materials as they observed, envisioned, extracted, processed, and changed animal bodies and tissues into new elements. Collectively, these papers present a strategy for examining connections between the spatial and temporal qualities of animal materials situated in human-scale material practices. The animal materials featured in this special issue serve as boundary objects across practical settings, contexts, regions, and cultural world settings that instrumentally link the history of science to anthropologies of craft knowledges.