Balsa wood is very soft and light with a coarse open grain, offering an excellent balance of strength and lightness. The density of dry balsa wood is about one third the density of other hard woods. Balsa wood is used to make very light, stiff structures in architectural modelling projects and for the construction of lightweight model aircraft. It is also a very popular material to use when making wooden floats for fishing, as it is low density but high in strength. Despite being very soft, balsa is classified as a hardwood and is the softest commercial hardwood available.