High Pressure Laminate (HPL) is composed of a resin impregnated kraft paper, a decorative paper and a clear melamine overlay. These sheets are bonded at high pressures and temperatures. The sheets are bonded to substrates such as MDF (medium density fiberboard) or particleboard.The resulting laminate is strong, durable and water resistant. ... A versatile product, HPL offers superior resistance against impact, abrasion and general surface wear. As its surface is impervious to water, it's ideal for use in a range of applications and particularly so, in washroom environments. HPL is made of 65% kraft paper and 35% thermosetting resin which both polymerise under heat and pressure.