3.3.2. Example entries in the exception table

3.3.2. Example entries in the exception table

Example 1

Let's return to example 2 from the F3 SEQUENCE OF SIGNATURES/SHEETS panel. Number of pages: 176, 8 pages per sheet, complete signature: 32 pages. The 16-page incomplete signature is the penultimate signature in the book block.

According to the pattern for the sequence of signatures in a block (nC+I+C), the default sequence is 4C+16+C, i.e. (4*32)+16+(1*32) – and this is shown in the F3 SEQUENCE OF SIGNATURES/SHEETS IN SEWN BINDING panel.
Add a new entry to the exception table: pages in incomplete signatures: 16 pages in complete signatures: 32 sequence definition: C+16+nC and selecting Acive exception will cause that every time a 16-page incomplete signature appears next to a 32-page complete signature, it will be offset behind the first complete signature

Example 2

Let's return to example 3 from the F3 SEQUENCE OF SIGNATURES/SHEETS panel. The imposition parameters set there for the 176-page file are: 8 pages per sheet and 32 pages in a complete signature. The 16-page incomplete signature is the penultimate signature in the book block.

If we want to split an incomplete 16-page signature into two 8-page signatures, which will be placed as the second and penultimate signatures in the book block, we must add the following entry to the exception table: C+8+nC+8+C.

The definition of the sequence C+8+nC+8+C means that the book block will consist of one complete signature, followed by an incomplete 8-page signature, then a block of n complete signatures, followed by another 8-page signature and finally a complete signature.

Currently, there are two entries in the exception table for situations where the complete signature has 32 pages and the incomplete signature has 16 pages. When entering a new exception, we selected the Active exception option in the Define exceptions dialog box. This automatically disabled the first exception, even though it also met the conditions. Only one exception that meets the conditions for the number of pages in a complete signature and an incomplete signatures can be active in the table. From that moment on, any incomplete 16-page signature will be divided into two 8-page signatures, and their placement will be according to your preferences

Example 3

This example is based on data from example 4 in the F3 SEQUENCE OF SIGNATURES/SHEETS panel. A 164-page file is to be imposed. The imposition parameters are: 8 pages per sheet, 32 pages in a complete signature. The incomplete 4-page signature is the penultimate signature in the book block.

If we want to increase the number of pages in an incomplete signature to 12 by adding one complete sheet from the previous signature, we add the following entry: nC+24+12+C

After applying the exception definition, the book block should by as follows (block of complete signatures (nC) + an incomplete 24-page signature (24) + an incomplete 12-page signature (12) + the last complete signature (C):

If you want to combine a 4-page signature with the previous complete signature (32 pages, thus creating a 36-page, oversized signature), add the entry: nC+36+C

Example 4

Number of pages per sheet = 4.
Number of pages in incomplete signatures = 4.
Number of pages in a complete signature = 24 (6 sheets per signature).

With 220 pages and the exception table disabled, 10 signatures will be created. Signature No. 9 will contain only 4 pages (one 4-page block). Such a large difference in the thickness of signatures – between a complete signature (6 sheets) and an uncompleted signature (1 sheet) – is a significant problem during the sewing process.

Such a signature can be eliminated by merging it, for example, with the previous signature (7 4-page signatures in total), provided that the sewing machine available at the printing house is capable of sewing 7 sheets at a time.

Another solution to this problem is to assemble the book block from 20- and 24-page signatures. This can be done using the context menu commands, defining the number of pages in each signature in turn, starting with the left signature.

As a result of changing the number of pages in the signatures, the following signature arrangement in the book block is obtained.

To create such a layout using an exception table, define the exception using the notation: 20+C+20+C+20+nC+20+C+20+C.

In this example, the number of pages in incomplete signatures (20 pages each) will be: 20 + 20 + 20 + 20 + 20 = 100.

The number of pages in completed signatures (C) will be: 24 + 24 + 24 + 24 = 96.

The number of pages assigned to the phrase nC in the exception definition will be: 220 – 100 – 96 = 24.

This number must be divisible by the number of pages in a complete signature (n must be an integer). Since 24 / 24 = 1, this means that n = 1.

In summary, for 220 pages, the number of pages per phrase nC is: 220 – (20 + 20 + 20 + 20 + 20) – (24 + 24 + 24 + 24) = 24, which allows the exception to be applied.

If the length of the default and actual signature sequences is too long for the panel, it is displayed in a tooltip.