Sheets of chipboard, MDF or fiberboard are most often used as the outer layer. Therefore, it is necessary to ask the seller what material was used in the manufacture of a phylenka. It is preferable to choose doors whose file is made of MDF, since the chipboard is able to distinguish formaldehyde. In addition, the doors from MDF, unlike wooden, are less prone to deformations. It is important to remember that the door in no case should be subjected to sharp temperature differences and high humidity.