This study regards the effect of technological aspects on mat compression during the manufacturing of low-density particleboards made of two low density species – i.e. poplar and pine. Using these materials, three-layer low-density particleboards (500 kg/m3) were prepared. Three series were manufactured: (1) neat pine, (2) poplar-pine (face layer and core layer, respectively) and (3) neat poplar boards. Measurements of real-time variations in mat core temperature, pressure, and mat thickness allowed for the analysis of the mat compaction. Selected mechanical properties (modulus of rupture, modulus of elasticity, and internal bonding) of the manufactured particleboards were determined. Raw material of lower density used for particleboard manufacturing required either prolonged pressing time or more intense heat transfer into the mat core. The highest strength values were obtained for the poplar-pine particleboards.