Holographic polymer-dispersed liquid crystals (H-PDLC) are able to store interference pattern through inhomogeneous polymerization associated to diffusion of the liquid crystal molecules. The final result is a phase separation giving rise to small liquid crystal domains separated by dense polymer regions. The original feature of the paper is the comparison of the grating built up in the H-PDLC medium with the one recorded in the same photopolymerizable system without the liquid crystal. The analysis is based on the diffraction efficiency curve recorded in real time and the characterization by atomic force microscopy of the different microstructured elements.