Three experiments examined whether the experience of individuating an object would affect the way that children of different ages would interpret its label. Participants were asked to remember a novel object and pick it out from sets containing either two similar objects (similar condition) or no similar objects (dissimilar condition). They were then taught a label for the object and tested for how broadly they generalized it. Because children in the similar condition had formed a more detailed representation of the object, they were expected to generalize its label less broadly. For artifacts, this effect was observed in 4- and 5-year-olds as well as first and second graders, but not in 3-year-olds or adults. For toy animals, no age group showed this effect, and the three oldest groups of children showed the opposite effect. Various explanations for why the consequences of individuating an object for the interpretation of its label depend on age of the learner and the object's ontological kind are discussed.