After being generated, a new idea is rarely perfect but must be clarified, improved, and developed in more detail. Unfortunately, idea elaboration and creativity do not always come together: many new ideas become less creative when elaborated. This research examines who elaborate new ideas the more creatively. We propose and test hypotheses that compare when creators elaborate new ideas they created (i.e., internal revision) vs. when creators elaborate new idea that they did not create (i.e., external revision). Drawing upon creative cognition theories, we propose that, on average, internal revision outperforms external revision because the original creators are more persistent. We further hypothesize that the advantage of internal revision over external revision depends on the initial level of creativity of the idea. Specifically, the positive effect of internal revision is strengthened for highly creative ideas; inversely, external revision is more beneficial when ideas initially lack creativity. We tested and found support for our hypotheses in an archival study of an online 3D printing platform with 13,912 prototypes. This research contributes to the creativity literature by advancing our knowledge of the creative processes after the idea generation stage. We empirically establish the causal effect of internal and external revision on creative elaboration and identify boundary conditions.