For the development of reflective flat displays, polymer liquid crystal composite is a good potential challenger material. Ln order to reduce the driving voltage and to enhance the brightness of the backscattered off-state, it is necessary to understand and optimise the composite formation. Based on a suitable liquid crystal and polymer couple, we describe a model for the fabrication of polymer dispersed liquid crystal. The influence of the main parameters on the composite production is studied. We choose the case of polymerization-induced phase separation, by means of ultra violet light polymerizing monomer. This study shows how the polymerization parameters control the droplet size and the remaining monomer content, both of which play a role in back-scattering and saturation voltage. We bring to light, the strong temperature sensitivity of PDLC formation and the necessary precautions to reach the optimum performance of the chosen liquid crystal-polymer couple. As this step is essential to exploit PDLC systems, it could also be systematically used to compare then under the best conditions.