The Ionized Cluster Beam (ICB) technique pioneered by Takagi and colleagues in Kyoto is an exciting new method for depositing thin films possessing novel microstructures and unusual properties, (see for example Ref. 1 for a review of recent work). These materials are of interest not only for their potential use in electronic applications but also because of their eminent suitability for fundamental high resolution studies of grain boundary structureThe HVEM's at the National Center for Electron Microscopy are employed in a complementary fashion to characterize fully the microstructure of ICB deposited Al films. In-situ annealing studies of the films are conducted in the 1.5 MeV Kratos HVEM taking advantage of its heating stage, excellent specimen chamber vacuum (10-8 torr), and high resolution video camera. The increased penetration at 1.5 MeV allows different film thicknesses of Al film to be examined as well as the regions of the foil where the silicon substrate remains backing the Al film. High resolution studies of the atomic structure of grain boundaries are performed on the 1 MeV JEOL ARM using its unique tilting stage and ability to image structures at the 0.15 nm level.