There are several acceptable ways to ascribe emphasis
to printed text. Two most common methods involve using italic
fonts (with italic font being more prevalent in officially published materials). At the same time, there is a number of ways traditionally deemed inappropriate by the publishing industry
. These include increasing distance between adjacent letters, changing font color, underlining text and changing interline distance.
In the recent years, many of these timeless industry conventions have been broken by the internet. This apparent lack of consistent standards has inadvertently challenged italics as the method of choice. Nonetheless, italic fonts, which celebrated their 500-year birthday in 2001, remain incredibly popular both in printed press and online publications.
Aldo Mannucci (Manutius) (1449-1515), Italian scholar, editor and printer, is credited with inventing italic type. He was the first to use it in a Virgil edition of 1501. While it might have been dedicated to the States of Italy (see Webster_1913 writup), Mannucci’s original intention was to emulate official hand-written documents issued by the Pope. Eventually when the type began making its way across Europe and beyond Italy's borders it became known as "italic".