Nanocomposites with tailored optical properties can provide a new degree of freedom for optical design. However, despite their potential these materials remain unused in bulk optical applications. Here we investigate the conditions under which they can be used for such applications using Mie theory, effective medium theories, and numerical simulations based on the finite element method. We show that due to scattering different effective medium regimes have to be distinguished, and that bulk materials can only be realized in a specific parameter range. Our analysis also enables us to quantify the range of validity of different effective medium theories, and identify design rules on how the material's free parameters should be adjusted for specific applications. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement