# Type area

Type area of ​​classic modernism, Bremer Presse 1928

As a type area or text area in which it is typography , the usable space on the side of a book , a magazine or other printing units designated.

The type area is limited by the ridges, i.e. by the unprinted spaces between the type area and the edge. The columns ( column set ) with text, graphics or images always belong to the type area. The so-called “living running headline ”, which, together with the page number, also contains brief information about the respective chapter content, is included in the type area; also footnotes . In contrast, the "dead running head", which only contains the page number, does not belong to the type area.

The art of typesetting is to design the page in a form or in a ratio so that it appears harmonious to the viewer. In order to achieve this mostly subjective goal, the printing trade makes use of various rules and systems. Among other things, dimensions are used in the division ratio of the golden section or approximated by neighboring numbers to the Fibonacci sequence , but various other systematics have also been used over the centuries.

A certain division scheme for the page always only applies to a certain page format of the paper.

## Bridges

Bridges

The margins between the type area and the edge of the paper are called bars . Each bridge has its own name so that there is no confusion between the edges.

Gutter (inner bridge)
Middle of the book, on the waistband
Outer bridge
outer sheet edge, including marginalia
Footbridge
bottom margin, including footer

As a rule, the webs are narrower towards the middle of a book than at the edge, since the pages touch each other there and thus the two internal webs look more like a unit of double width. Therefore, the inner and outer webs are often in a ratio of 1∶2 to each other.

Sometimes the gutter is only used to describe the one-sided binding margin that reserves the part of the physical page that is necessary for binding or punching. The visible space is then called the inner walkway . This applies in particular to word processing on the PC, where the printout is made on individual pages (e.g. A4) and not on larger sheets that are later folded and trimmed. If such a lateral binding margin is 12 mm wide, the usable aspect ratio in portrait format is exactly 2∶3 (198∶297 mm), while 26 mm results in approximately a golden rectangle for the side mirror and 17 mm binding margin in landscape format is exactly 4∶3 (280 ∶210 mm).

In the Middle Ages , paper with an aspect ratio of 2∶3 often had a ratio of gutter ∶ head bridge ∶ outer bridge ∶ foot bridge of 2∶3∶4∶6, and for paper with 3∶4 also 3∶4∶6∶8, generalized x ∶y∶2x∶2y with an aspect ratio of the sheet and type area of x∶y .

Most word processing programs use a more mechanical ratio of 5∶5∶5∶4 by default with a base size of 20mm, 25mm or 1 inch (25.4mm).

Preset type area of ​​an A4 page in Microsoft Word (dimensions in mm)
normal narrow medium wide mirrored
Gutter (binding margin) 0
Inner bar (left edge) 25th 12.5 18.75 50 31.25
Outer bar (right edge) 25th 12.5 18.75 50 25th
Footbridge (bottom margin + footer) 20th 12.5 25th
Text width 160 185 172.5 110 153.75
Text height 252 272 247

DIN 5008 provides a template for business letters on A4 paper with a gutter of 25 mm, divided into 20 mm binding margin and 5 mm inner margin, and an outer margin, into which, for example, the information block protrudes 10 mm, of 20 mm; For other types of text, adapted bars are also permitted, e.g. an outer correction margin of 50 mm for specialist work or a marginal column. For the letterhead , either 27 mm (Form A) or 45 mm (B) and an additional gap of 5 mm are required; provided, while the standard does not specify the heights, positions or vertical distances to the lower edge of the sheet of footnotes and footers, which means that the footbridge and thus the text height is not specified. The sheet is also divided vertically into three areas by the intended fold at the standard fold marks for DL ​​envelopes, which are approximately 6∶7∶7 (A) or 7∶7∶6 (B), so that the two longer sections Together with the width of the sheet, form a square with an edge length of 210 mm.

Type area of ​​an A4 business letter according to DIN 5008 (dimensions in mm)
Form A Form B
Gutter (binding margin) 20th
Inner bar (left edge) 5
Outer bar (right edge) 20th
Footbridge (bottom margin + footer) free ≥ 20
Text width 165
Text height ≤ 245 ≤ 227

## Classic construction

Various methods are possible for dividing the area of ​​a book page into the rectangular type area and the surrounding webs. The classic construction method uses diagonal lines drawn over a double page and the two individual pages. The corner points of a rectangle lie on the diagonals, which is then defined as a type area by additional auxiliary lines.

The following example shows the construction for a double page with single pages left ( verso ) and right ( recto ) in a format based on a ratio of the page lengths of : ${\ displaystyle 1: {\ sqrt {2}}}$

1. Basic construction - diagonals are constructed over the double side from the bottom outside upwards, as well as for each of the two individual sides.
2. Construction of a type area - corner points of the rectangle come to lie on the diagonals. The further up and inside the upper inner corner is selected, the larger the type area and the smaller the ridges.
3. Limitation of the type area according to Villard's canon, approximately in the division ratio of the golden section .
4. Subdivision of the type area by a usage grid, for example in nine divisions (9 × 9).
Type area of ​​an A4 page according to construction with golden ratio (dimensions in mm)
relationship Partial page Single page
Gutter 100 23.3 35
Outer bridge 198 46.7 35
Footbridge 280 66
Text width 594 140
Text height 840 198

## Grid division

Type area construction of a double page with grid division / nine division

The grid division divides the page horizontally and vertically into the same number of grid fields. One grid field remains free on the inner and upper edge, two on the outer and lower edge, i.e. 1∶1∶2∶2. Among other things, 9 × 9 fields (division into nine) are common, which provides practically the same results as the construction according to the golden ratio.

Type area of ​​an A4 page according to construction with nine division (dimensions in mm)
Segments 1∶√2 2∶3 1∶φ
Gutter (binding margin) - 0 12 25.5
Inner bridge 1 (1.5) 23.3 (35) 22 (33) 20.5
Outer bridge 2 (1.5) 46.7 (35) 44 (33) 41
Footbridge 2 66
Text width 6th 140 132 123
Text height 6th 198