Evaporative pre-concentration is energy conserving and benefits from minimal intervention in environmental monitoring for sustainability. Drops of specific volume falling cleanly through the superhydrophobic hole method here are found to work on woven mesh (wire diameter = 57 μm, pitch = 125 μm) but not on plate substrates. Their conception as solid spheres was not borne out in volume to hole diameter trends, and they can also be retained on the substrate despite high levels of inclination.