The forming box is designed to prevent the following conditions, as of the sagging of wire between the chest roll and the first dewatering element of fourdrinier, reduce the dewatering affect of the chest roll as well as to improve the spreading of the pulp along the width of the wire. The box is a welded metal structure is made of corrosion-resistant steel. The forming box is attached to the columns which allow it to be moved relative to the chest roll.

The forming box is equipped with the first wide foil and the several narrow foils (50 mm)with an angle of inclination to the wire of 0 °. The foils can be made of high density polyethylene(HDPE) or ceramic. Taking into account the wear of plates, the forming board is adjustable in height. The foils are attached to the forming board using T-rails.
The forming boxes are made for paper machines with reel widths from 1680 to 4200 mm.