The 2006 series also saw several new security features, including brighter background colours, a micro-printed holofoil on the 50- and 100-dollar notes, a tapered serial number, and a security thread woven through the note. On 26 September 2013 the Central Bank of the Solomon Islands issued a new 50-dollar note with hybrid security features by printers De La Rue, and announced it to be the first of a series of new banknotes over the course of five years as older notes wore out.