Hollow and core-shell rutile particles were synthesized, and their opacifying power in a cellulose matrix was compared with that of commercial solid rutile particles. It was found that the opacifying power of hollow polycrystalline rutile particles was superior to that of a commercial rutile pigment in a highly pressed bleached fiber matrix, depending on cavity size, whereas the opacifying power of silica-rutile titania core-shell particles was found comparable to that of commercial rutile at constant titania loading. The light scattering efficiency of titania core-shell particles was also shown to be dependent on the light scattering efficiency of the core material. The light scattering efficiency of the polycrystalline silica cores was found to depend on calcination temperature and crystal structure.