The cover art illustrates "meatball-spaghetti" analogy, which has been used to generate and stabilize active metallic nanoclusters. This analogy is based on the premise that the aggregation of the meatballs (nanoclusters) can be prevented if enough spaghetti (flexible silicones) is present to physically wrap the meatballs during the formation process. See B. P. S. Chauhan, R. Sardar, U. Latif, M. Chauhan, and W. J. Lamoreaux, Acta Chim. Slov. 2005, 52(4), 361-370.