An optimized screener is designed with the consideration of countless variables, and evaluating performance begins with identifying an operational objective. This objective is often the production of a single product through the removal of oversize or fines particles (or both), and can sometimes be several products through grading with a multiple-deck screener. Given the many factors that go into screener design, how does a company find the right balance? More importantly, what are the best practices for evaluating screening performance?