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Schlieren texture of a nematic film with surface point defects (boojums). This picture was taken under a polarization microscope with polarizer and analyzer crossed. From every point defect emerge four dark brushes. For these directions the director is parallel either to the polarizer or to the analyzer. The colors are newton colors of thin films and depend on the thickness of the sample. Point defects can only exist in pairs. One can see two types of boojuns with "opposite sign of topological charge"; one type with yellow and red brushes, the other kind not that colorful. The difference in appearance is due to different core structures for these defects of different "charge".