An optical tube assembly and method of manufacture include at least one optical waveguide, at least one dry insert that generally surrounds the at least one optical waveguide, and a tube. The dry insert includes a tape and at least one filament attached to the tape, thereby forming a plurality of loops. In preferred embodiments, either the tape or the at least one filament of the dry insert has a water-swellable component. Additionally, the optical tube assembly may be a portion of a fiber optic cable.