Conventional silica optical fibers can be embedded into composite structures or packaging to provide structural monitoring capabilities. In this paper, the microbending optical losses induced by the packaging of a sensing optical fiber into a sandwiched glass-fiber reinforced structure are investigated experimentally and by simulations. Results show that the positioning of the optical fiber within a plain-weave glass fiberreinforced structure has a critical effect on microbending optical losses due to potentially induced microdeformations of the optical fiber's cylindrical shape. Similar analysis is also carried out with the use of a 1D glass-fiber layer packaging, demonstrating lower residual microbending losses after manufacturing. By the proper positioning of an optical fiber containing a series of wavelengthmultiplexed fiber Bragg grating (FBG) sensors over a 2D plainweave glass fabric, a 10-fold improvement in the induced optical losses is demonstrated, increasing the optical power that reaches the interrogating unit and allowing the monitoring of hundreds of meters over glass-fiber structures. Although all the analysis is focused and verified using a series of FBG sensors, the results and conclusions related to the induced microbending losses are also valid and useful for distributed optical fiber sensing approaches.