Design for Lean Six Sigma (DfLSS) is a systematic methodology to design new products or processes so that quality is built into every phase of product design. It is also a proven process improvement methodology used for improving existing products through redesign, and currently widely being employed across chemical industry. This paper describes the application of DfLSS methodology for the formulation and process design of an improved emulsion latex for emulsion-aggregation toner application. A systematic IDOV process (Identification, Design, Optimization and Validation) was demonstrated from the point of view of the research scientist/engineer. The key customer requirements were “designed-in” via the latex key properties (Tg, Mw and particle size) and optimized through DOEs (design of experiment). The resulting latex process is more robust against several sources of variation (raw material quality, operation and equipment aging). This was accomplished through a robust design and implemented at the manufacturing scale.