Flush doors have simple door designs that have perfectly smooth surfaces on both sides. They are manufactured by sandwiching plywood or blockboard over a light hardwood/cardboard frame. Laminates or veneers might be used to finish them. These doors have excellent dust, heat, and noise resistance.
Solid core flush doors are made using wood that is mostly composed of minerals. These doors are usually made by major plywood combining different types of particle board, laminate core, cross band, and face wood veneers.