Separating oil and water is a major problem across many industries, and the challenge is only exacerbated with stabilized emulsions whose drop sizes scale down to the micro and nanometer range. Advances in membrane technology, such as the introduction of superwetting and nanomaterial-based membranes continue to make these technologies among the most viable treatment options available. Given their scale and desirable wetting characteristics, carbon nanotube (CNT) based membranes have attracted considerable attention for oil-water separation with studies reporting fluxes orders of magnitude higher than what is commercially available [9-12].  In spite of these films’ great potential, most studies in the literature have solely focused on films with random morphologies of SWCNT stacking with little attention given to the order of stacking as a tunable parameter to influence filtration performance. Moreover, the transfer of such films has not been widely explored onto not only more porous, but also cheaper substrates, such as filter paper, in order to demonstrate the capability of the method. In this work, we show that in-plane horizontal alignment of SWCNT films can be incorporated as an additional degree of freedom to achieve enhanced selectivity. Our results have significant implications on the potential of using SWCNT films in fabricating ultrathin and tunable membranes for oil-water separation.