We thank David Cotrell and Judith Devaney of the NIST Mathematical and Computational Sciences Division for the numerical evaluation of the reduced thread instability growth rate q(Λ) / q∞ from the theory of Mikami and Mason [41] and for the determination of the approximant [42] for q(Λ) / q∞ shown in Fig. 4(b), respectively. We also thank Jai Pathak, Steve Hudson, and Kalman Migler of the Polymers Division and Edward Garboczi and Jeffrey Bullard of the NIST Materials and Construction Research Divisions for their helpful comments on our paper. Finally, we acknowledge the NIST Center for Theoretical and Computational Materials Science for its crucial financial support at an early stage of this project.