The Guardian newspaper has relaunched with a new size and a new look, becoming the first national paper to print in a mid-size format.
The paper has been given a more contemporary look
The size, part way between a tabloid and a broadsheet, is known as the Berliner, and is used by many papers in continental Europe.
The redesign also sees every page being printed in colour.
The relaunch aims to win back readers who moved to the Independent and Times when they changed to tabloid format.
Both papers began printing in a tabloid format in 2003, and eventually abandoned broadsheet editions altogether.
Guardian editor Alan Rusbridger said Monday's change, which also includes a new masthead and typeface, was a "radical one".
"The change from broadsheet to the so-called Berliner format has led to a thorough re-evaluation of most of the things we do, both editorially and commercially," he said.
"No newspaper ever stands still. But this change is, by any standards, a radical one."
"The challenge for us was to remain true to our journalism, now attracting a record worldwide audience online, while at the same time finding a modern print format for a new generation of readers in this country.
"We believe we've found it with the Berliner format, which combines the portability of a tabloid with the sensibility of a broadsheet."
The relaunch has taken 18 months of preparation at an estimated cost of £80m.
The company has bought three 44m (144ft) German printing presses to print in the new size.
The relaunch will be accompanied by a TV, poster and press advertising campaign.