Over time, the term MDF has become a generic name for any dry process fibre board. MDF is typically made up of 82% wood fibre, 9% urea-formaldehyde resin glue, 8% water and 1% paraffin wax.[4] and the density is typically between 500 kg/m3 (31 lb/ft3) and 1,000 kg/m3 (62 lb/ft3).[5] The range of density and classification as light, standard, or high density board is a misnomer and confusing. The density of the board, when evaluated in relation to the density of the fibre that goes into making the panel, is important. A thick MDF panel at a density of 700–720 kg/m3 may be considered as high density in the case of softwood fibre panels, whereas a panel of the same density made of hard wood fibres is not regarded as so. The evolution of the various types of MDF has been driven by differing need for specific applications.

Types 

Ultralight MDF plate (ULDF
Moisture resistant is typically green
Fire retardant MDF is typically red or blue

Although similar manufacturing processes are used in making all types of fibreboard, MDF has a typical density of 600–800 kg/m³ or 0.022–0.029 lb/in3, in contrast to particle board (160–450 kg/m³) and to high-density fibreboard (600–1,450 kg/m³).