A novel plastic with useful properties can easily be recycled again and again Since the synthesis of the first synthetic polymer in 1907, the low cost, durability, safeness, and processability of polymers have led to ever-expanding uses throughout the global economy. Polymers, commonly called plastics, have become so widely used that global production is expected to exceed 500 million metric tons by 2050. This rising production, combined with rapid disposal and poor mechanisms for recycling, has led to the prediction that, by 2050, there will be more plastic in the sea than fish ( 1 ). On page 398 of this issue, Zhu et al. ( 2 ) report an important step toward addressing this problem with the synthesis of a plastic with mechanical properties comparable to those of commercially available plastics, but with an intrinsically infinite recyclability.