Steiner equiangular tight frames redux

An equiangular tight frame (ETF) is a set of unit vectors whose coherence achieves the Welch bound, and so is as incoherent as possible. ETFs arise in numerous applications, including compressed sensing. They also seem to be rare: despite over a decade of active research by the community, only a few construction methods have been discovered. One known method constructs ETFs from combinatorial designs known as balanced incomplete block designs. In this short paper, we provide an updated, more explicit perspective of that construction, laying the groundwork for upcoming results about such frames.