Window profiles are made of engineered pine wood. Bonding layers of wood prevents its deformation due to its long use and eliminates wood defects (e.g. knots, resin blisters). Impregnation of wooden profiles increases their life and prevents blue stains, fungi and mould. Three coats of organic varnish protect the profiles from discolouration. The thickness of the casement and the frame in SOLID+ option is 130 mm, which guarantees great heat insulation.