To explore the applicability of NHSK paper for condensation control, the behavior of condensation at the surfaces of these films was also studied using an ESEM. Examples of a series of still images recorded from in situ ESEM condensation experiments on SWCNT buckypaper and NHSK-54 paper are shown in Fig. 4, along with rose histograms of condensation CA (cCA) data. For the measurement of cCAs, sample surfaces were angled towards the gaseous detection device (GDD) such that forward edges of the condensation droplets' contact circles could be observed, from which the cCA could be calculated (derivation available in the Supporting Material, Figs. S1 and S2). If the droplet oriented at a tilt angle ϕ can be assumed to form a spherical cap with radius R and contact circle radius a, it will appear to the viewer to have a total “observable altitude” B, defined as the distance from the top of the observed arc of the spherical cap to the point on the contact circle closest to the GDD. a can be calculated from the quadratic equation as