All the doors frames and trims in the “Effetto Legno” collections Materik, Grafite and Trame are completely water-repellent. An important asset to the high quality of Bertolotto Porte products. The structure and door leaf, made with a solid wood perimeter and honeycomb core are coated with ABS layers on all four sides and bonded with polyurethane adhesives. The double-sided panels are made of water-repellent certified MDF, the frames are made of FSC-certified, water-repellent virgin wood LSB. Water-repellent certified MDF trim.