Flexible polycarbonate tubing with bore sizes ranging from 500 to 2000 micron was used to make hollow waveguides. Silver/silver iodide and copper/copper iodide were chosen as the metal and dielectric layers respectively. The Ag/AgI waveguide loss at lambda equals 10.6 micron is below 0.1 dB/m for bore sizes over 1200 micron. The small bore size waveguides are single mode even on bending, while the larger bore size waveguides are multimode. The measured loss at 10.6 micron for a 1000 micron bore size Cu/CuI waveguide is 0.33 dB/m. An approximately flat transmission window was obtained for Cu/CuI waveguides in the wavelength region from 2 to 16 micron.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.