Book size

The book format indicates how many sheets can create a printer from a sheet of paper, traditionally the dimensions of a Roman parchment sheet are based. An unfolded sheet is called Atlas format, double or large folio. Folds to a bow for the first time, we get the folio ( 2 sheets ), you fold it a second time, you get the quarto ( 4 sheets ), etc. The size varied depending on the availability of the skins, which you processed parchment.

Previously letterpress

In letterpress printing, the 15th - 19th Century, the format is also specified by the number of folds of the paper sheet. The size of the paper sheet fluctuated but regionally according to the respective measurement system. Common sheet sizes were between 20 × 30 and 30 × 40 cm. In addition, the book size varied by the amount of pruning after binding. The ratio of height to width is different depending on the type of folding. For the formats 6 °, 12 ° and 24 °, the width is in proportion to the amount narrower than in the formats 2 °, 4 °, 8 ° and 16 °.

In old prints ( published before 1800 ), it is recommended to use the size specified this old book formats.

In landscape mode, a " transverse" prefixed: Across 8 °, horizontal 2 °. Striking non-standard formats can not preceeded by " large" and are marked "small": gr 2 °, kl. 8 °, etc.

Format determination

A determination is easiest on the basis of Gatherings possible because an arc results in a situation that makes, for example, in the quarto 8, in Duodezformat 24 pages (see table above). The layers were marked with letters and the individual sheets of documents with Roman numerals, so that, for example, in the quarto sheets of the first layer with A, A II, A III and A IV are indicated; usually, however, only the first (front ) half of the leaves was called. But it can also happen that from a sheet two layers were made so that for example a Duodezband only six sheets per layer contains instead of twelve.

Determining format and the running direction of the Papierkämmung can be used. The so-called web or transverse ribs (the ones lying at a distance of about 2.3 cm fins be perpendicular to the well knit rib or longitudinal ribs) at 2 °, 6 °, 12 ° ( mostly) and 16 ° vertical, at 4 °, 8 ° and 24 ° horizontally (relative to portrait formats ).

Standard formats according to the Prussian Instructions

Since 1883 efforts have been made in Germany to unify the sheet sizes. It emerged 12 normal formats, of which the number one unbroken or plano measured in 33 × 42 cm. For the bibliographic description of the books Prussian Instructions emerged ( PI), which set out standard book sizes. Here, the old names folio, quarto, octavo, etc. have been taken, however defined entirely differently. To classify served only the height of the spine without regard to the sheet folding and proportion. Background was the space-saving installation of the same high books on the shelves.

Generally one can say that the formats are considerably larger after PI than by the traditional definition. So one octave band is after PI up to 25 cm and thus includes Quart, octave, duodecimo and all smaller formats in the traditional sense a. In other countries, different rules applied.

Through various printing, binding and cutting techniques varies the size of the finished book. Therefore, the German Library in Frankfurt am Main has created a policy:

Is a book the width greater than the height, it is called cross formats, such as " across 8 ° ".

Today's rules

Today libraries are using in German-speaking mostly in 1976 established rules for alphabetical cataloging (RAK ), based on the International Standard Bibliographic Description ( ISBD ). Thereafter, the height of the spine is recorded in centimeters without a format category is specified when cataloging. Booksellers and antiquarians give only the amount often to the width of a book or a format category. This also applies to some foreign regulations.

Especially in letterpress there because of the convolution preceding enlargement and reduction ratios trailing ( English only English-speaking countries ):