The term “broadsheet” is used both to refer to a generic paper size and to specific types of publications that have historically been produced on this paper. The classic example is a wide-circulation newspaper, with the broadsheet size being preferred by many newspaper publishers. Newspapers that are intended to act as major news authorities are classically printed on pieces of paper of this size.
Unlike many other paper sizes, which include very precise dimensions, the dimension of a broadsheet can actually vary considerably. As a general rule, the sheets are vertically long and horizontally short, with a length of at least 22 inches (56 centimeters) and a width which can vary. When full size, a sheet of paper is printed and folded to create four pages — a front and back and two inner pages. A half broadsheet is a single piece of paper printed on both sides with no fold. For convenience in distribution, these papers are often folded in half lengthwise, but the fold does not affect the page count.
The origins of this paper size appear to lie in the 1600s, when early newspapers began printing half broadsheets with major news of note. The size was also used for song lyrics, posters, and other informational materials. Over time, news producers began to adopt the full size, and eventually additional sheets were interleaved to create the newspaper. The term was used to refer to newspapers as well as advertising materials printed on these large sheets of paper.
Several explanations have been posited for why the large broadsheet paper size became so popular. In the days of single-sheet publications, the larger the paper was, the more information could be printed on it, which may have been a factor. Historically, taxes were also calculated by the number of pages, rather than their size, so using large pages would have reduced the total number necessary, thereby lowering tax rates for a publisher.
The real explanation appears to lie in the traditional association between large things and increased authority. A broadsheet-sized publication looked more official, respectable, and authoritative than a smaller newspaper. It was also harder to print, which is why many producers switched to the tabloid size, which is about half as big. The implications of the larger size were that the paper was a respectable authority that could afford the oversized presses needed to produce broadsheets, as opposed to a cheap, low-market tabloid that was forced to use a smaller paper size. Of course, most modern presses are fully capable of handling the large size, but the link between “broadsheet” and “respected authority” continues to exist in many eyes, which is why traditionally-sized papers attract comment when they switch to the smaller, tabloid size.