To promote learning and transfer of abstract ideas, contemporary theories advocate that teachers and learners make explicit connections between concrete representations and the abstract ideas they are intended to represent. "Concreteness fading" is a theory of instruction that offers a solution for making these connections. As originally conceived, it is a three-step progression that begins with enacting a physical instantiation of a concept, moves to an iconic depiction and then fades to the more abstract representation of the same concept. The goals of this paper are: (1) to improve the theoretical framework of concreteness fading by defining and bringing greater clarity to the terms abstract, concrete and fading; and (2) to describe several testable hypotheses that stem from concreteness fading as a theory of instruction. Making this theory of instruction more "concrete" should lead to an optimised concreteness fading technique with greater promise for facilitating both learning and transfer.