Holograms have been constructed in photopolymer materials which give bright, low-noise images. These holograms are of the volume type and have no surface variations in all but a few special cases. They are constructed in virtually real time and in situ, requiring no processing. Materials sensitive to both uv and blue-green radiation have been used. In this paper, the mechanism of hologram formation is examined. Experimental results on sensitivity, spatial frequency response, particle scattering noise, and nonlinearities are discussed. A few holographic applications of the material are presented.