We present a new procedure for protecting micro-optical fibers (tapered fibers) by using the 3-dimensional (3D) printing technology.A standard single-mode optical fiber was tapered down to the diameter of 1 μm and embedded in a polymeric matrix obtained by an additive manufacturing routine.We show that the proposed structure protects the fiber taper against environmental humidity while keeping permeability to gas flow and the possibility of the realization of gas detection experiments.To our knowledge,this is the first time 3D printed casings were applied to protect fiber tapers from humidity deterioration.We envisage this new approach will allow the development of new fiber taper devices to better resist in humid environments.