Using chemical pulp is more expensive to produce paper than mechanical pulp or recovered paper, but it has better strength and brightness properties. Softwood kraft pulp is used to provide the required strength when producing light-weight publication papers. Fine papers (e.g. copy papers, writing papers, etc.) are an example of the type of paper produced mainly from hardwood pulp, which is reinforced by a minor amount of stronger and more expensive softwood kraft pulp. Pine and spruce provide the strongest pulp (e.g. softwood kraft), while hardwood kraft is produced from birch, eucalyptus, aspen, acacia and many other mixed tropical species.