An optical tube assembly having at least one optical waveguide, at least one dry insert, and a tube. The at least one optical waveguide is disposed within the tube and generally surrounds the at least one optical waveguide. In one embodiment, the dry insert has a first layer comprising a felt having at least one type of non-continuous filament. The dry insert may also include a plurality of water-swellable filaments. In another embodiment, a dry insert has a first layer, a second layer, and a plurality of water-swellable filaments. The first and second layers are attached together at least along the longitudinal edges thereof, thereby forming at least one compartment between the first and second layers and the plurality of water-swellable filaments are generally disposed in the at least one compartment. The dry insert also is advantageous in tubeless cable designs.