Previously, we have reported on high-density photon-gated spectral hole burning in europium-doped alkaline earth sulfides. Enhanced inhomogeneous broadening of the zero phonon line (ZPL) has been achieved by embedding MgS:Eu 2+ and CaS:Eu 2+ in PMMA and by compacting the sample by other means. We investigate the inhomogeneous broadening as a function of the molecular weight and the concentration of PMMA. Changes in both the line shapes and the line widths of the ZPL were observed. With the enhanced broadening a much larger number of persistent power-gated holes have been burned in the ZPL.