 Following the discovery of the platinum group of metals which include ruthenium, osmium and iridium, "a small quantity of iridium was isolated and used on the iridium-tipped gold dip pen nibs of the 1830s".Today, nibs are usually made of stainless steel or gold alloys, with the most popular gold content being 14 carat (58⅓%) and 18 carat (75%).Titanium is a less common metal used for making nibs.