The article outlines the development of AKD (alkylketene dimers) size emulsions, first brought out in 1955 as Aquapel, and alkaline curing wet-strength resin, known as Kymere 557. The combination of AKD size and polyamide resins used in beverage cartons produces a paper with a life span of 400 years. The article also mentions the recent development of a self-retaining cationic dispersed rosin size, Hi-pHase sizing agent. This allows the use of rosin-alum with minimal alum and at higher pH.