The report gives results of a full-scale investigation of the performance of a variety of filter media, to provide technical and economic information under high-velocity conditions (high gas/cloth ratio). The fly ash emission studies demonstrated that woven fiberglass fabrics and felts made from Teflon and Gore-Tex laminate were capable of meeting State emission code requirements at gas/cloth ratios of 4/1 to 6/1. The economic analysis showed that, in terms of annualized cost, the gas/cloth ratio, initial bag cost, and bag life represent the greatest potentials for cost reduction. Pressure drop reductions can lower operating cost, but they have only secondary impact on annualized cost. The analysis compares the effects of incremental changes in bag life, gas/cloth ratio, and bag price on total annualized cost.