Laminations made with blends of metallocene polyethylene (m-PE) and high-pressure low density polyethylene (LDPE) were prepared to investigate the effect of the former resin on heat sealing performance. According to various experimental studies of seal strength, hot tack and differential scanning calorimeter (DSC), it could be concluded that percentages around 15% of m-PE allow the obtainment of the optimal balance for heat sealing properties and cost. Using the interdiffusion theory of heat sealing, a thorough discussion of the results was done.