The foam finishing technology (FFT) process is a novel application system for treating porous substrates with foamed chemicals at very low wet pickups. It involves the use of a rapidly-breaking low-density foam or froth as the delivery medium for finishing chemicals, precise metering and flow control for delivery of foam to the substrate, pressure-driven impregnation of the foam into the substrate, and an applicator system designed to allow uniform high-speed application and collapse of the foam in a single step. The semi-stable foam is necessary to get spontaneous foam collapse and spreading though the substrate, and is in contrast to stable foams specified in various foam coating processes normally requiring a separate step to break and distribute the foam through the textile material. An analysis of variables in the FFT process is presented. Manipulation and precise control of the key variables make possible the exceptional versatility of the process in applying a wide variety of chemical agents to substrates ranging from lofty to paperlike nonwovens. A production case history of the introduction and evolution of uses of the FFT applicator system in finishing corduroy, bottom weight, and industrial uniform fabrics is presented. Use of a dual head/dual feed FFT applicator allows sequential application of resin and softener to the face pile and hand builder/binder to the back of corduroy without an intervening drying step. Wet-on-wet applications are also run with excellent add-on control. Process savings from reduced energy consumption, higher chemical efliciency, and increased production rates are documented to illustrate the rapid pay-back on investment in the FFT applicator system. Most significant is the improved fabric quality evident from the greater loft and desirable handle of FFT-treated goods.