Here we describe the standardised protocol used by the Canadian Airborne Biodiversity Observatory (CABO) to measure leaf spectral reflectance and transmittance, using an integrating sphere fitted to a portable full-range field spectroradiometer, for the special case where an individual leaf is too small and/or too narrow to entirely cover the reflectance or transmission port of the integrating sphere. Briefly, six arrays of mature, healthy and sunlit leaves from a canopy plant are arranged on a custom sample mount, and are then used for measurements of adaxial reflectance and transmittance. Reflectance measurements are referenced to a calibrated Spectralon® disk and corrected for stray light. Our leaf spectroscopy protocol is an adaptation of that of Noda et al. (2013) to the SVC DC-R/T sphere, and also builds from protocols by the Carnegie Airborne Observatory and the SVC integrating sphere user manual.