Abstract: Composite liners (such as acoustic panels, fan track liners, and/or ice impact panels or boxes for turbofan engines) and techniques for forming composite liners. In some examples, the composite liner includes at least one region comprising a reinforcement architecture comprising a matrix material, a plurality of relatively tough polymer-based reinforcement elements, and a plurality of second reinforcement elements. The plurality of relatively tough polymer-based reinforcement elements and the plurality of second reinforcement elements are embedded in the matrix material.