It is widely agreed that an artwork having certain non-aesthetic properties explains its having a certain aesthetic property. One interesting feature of such an explanation is its selectivity—it cites only some of the non-aesthetic properties on which the presence of the aesthetic property depends. Hence a question arises as to what distinguishes the selected non-aesthetic properties from the unselected ones. I answer this question by proposing a selection principle modeled on Laura Franklin-Hall’s selection principle for causal explanation, according to which (...) an explanation selects a package of factors that maximizes the ratio of delivery to cost. (shrink)