Using X-ray reflectivity, we have investigated the vertical ordering of multilayers of an asymmetrically substituted triphenylene derivative. A value of 1.37 nm is found for the thickness of an individual monolayer. Detailed fits for the reflectivity data have been performed. The corresponding electron density profiles suggest that very smooth, regular Y-type films are formed. The absence of clear Bragg peaks in the X-ray reflection curve and the small electron density fluctuations in the multilayer can be explained by an interdigitating packing of edge-on oriented disks in adjacent layers.