  We investigated the utility of free-standing graphene as a transparent sample
carrier for imaging nanometer-sized objects by means of low-energy electron
holography. The sample preparation for obtaining contamination-free graphene as
well as the experimental setup and findings are discussed. For incoming
electrons with 66 eV kinetic energy graphene exhibits 27% opacity per layer.
Hence, electron holograms of nanometer-sized objects adsorbed on free-standing
graphene can be recorded and numerically reconstructed to reveal the object's
shapes and distribution. Furthermore, a Moire effect has been observed with
free-standing graphene multi-layers.
