PDF Imposition well done with Callas PDFToolBox

One of the most critical prepress steps is PDF Imposition. A lot of good imposition solution exist. Please allow us to introduce you Callas PDFToolBoxAlthough this software is primarly intended to PDF preflight and correction, it does embed a powerful and useful imposition engine.

We will show how to impose our files thanks to PDFToolBox and supplied imposition schemas but also customizing our own imposition files. At last, we will maximise our imposition process with the help of the great IndyFont product from Indicripts.

It’s up to you to choose to impose your files with the standalone PDFToolBox application or by using the Adobe Acrobat plugin. One may prefer to use PDFToolBox Server through Command Line or in combination withEnfocus Switch. Whatever you decide, we hope this post will help you understanding PDFToolBox imposition peculiarities.

A) Imposition made easy

Impose a file with PDFToolBox is damn easy. Launch the app and load your PDF file.

Chargement d'un fichier dans Callas PDFToolBox


In the “SwitchBoard” panel, click on “Arrange” puis sur “Impose”. Set your imposition then click on “Execute”.


Panneau Switchboard pour l'imposition


Voilà, imposition done in a few clicks !

Imposition générée par PDFToolBox

Several imposition schemes are delivered by default. It’ likely that the one you need is in there. But of course, you can still add your own imposition scheme.

B) Customize your imposition

To create your own imposition rules, you need two complementary files :

  • sheetconfig : sheet properties (sizes and available slots).
  • runlist : layout instructions within a sheet.

In other words, on one side you say how some sheet is usable and on the other side how you want to use it.

relation entre sheetconfig t runlist

In the above figure, you can see that the runlist links pages from rank 1 to n to slots without any concern on the size or location. If some slot isn’t available, the engine stops and returns the original file. This separation is interesting as it favors reusability.

Syntax is specific. The sheetconfig sets slots as a pseudo table :

Syntaxe d'une sheetconfig

The runlist is more about instructions in a minimalistic programming language.

Syntaxe d'une runlist

Don’t be afraid. The reference manual says all. To add your own files, simply drag them into the specific folder. To open this folder, call the “Manage imposition” menu in the bottom of the switchboard :

Ajouter des schemas d'imposition à PDFToolBox


One limitation is that you can’t add vectorial objects on the sheet. You can certainly add cropmarks but not cuemarks.

Marques de collationnement

Cuemarks help operator controlling the book assembly.

What solutions then ?

Add cuemarks with PitStop Server ?

PitStop Server would allow adding vectorial objects with a dedicated Action Script. Possible yet oversized.

Superpose a file ?

PDFToolBox allows PDFs merging. We could have a separate cuemarks PDF file and then superpose it. If marks are constants, that’s a way to go. Problem is, what if the marks have to vary from page to page ?

The trick

In our real life case, our client wanted that useless pages can be spotted in the stack thanks to a larger cue mark. So in the book assembly process, an operator could easily retire these pages.

Marques de collationnement normales

No useless pages here, normal cue marks are used.

Marque de collationnement étendue

One slot is empty here. We use a larger cue mark to spot it.

So it’s all about adding a larger cue mark when a spot is empty. A tough challenge at first but then solution appeared so simple. One thing certain, cuemarks have to be added within the impostion process. Later, it would imply to localize sheets with empty slots.

But how…? One thing you can do for sure is add text with the runlist instruction “PlaceText“. What if my text was my cue mark ? Windings fonts are full of squares. But I wanted a better control over the font, so I chose to do mine. So I used the amazing  “IndyFont” product from IndiScripts. With IndyFont, you can create your own OpenType fonts from within InDesign.

Ouvrir IndyFont

I just need a “square” character. If needed, i will repeat it. So I run IndyFont and pick on character : 1.

Page type avec IndyFont

IndyFont generates a document. I draw my square on page 1 and run IndyFont over.

Générer une font avec IndyFont


I export my font with the “Export OTF” button. Once I chose a destination folder, I get a fully usable CUEMARKS font for my imposition within PDFToolBox.

With the following instructions,  I am telling the imposition engine to write texts with my font.

Set TextFont “CUEMARKS”
Set TextSize “5mm”

So while imposing, I can add standards marks where I need it :

PlaceText          Slot_31        “1”

Or if I need larger marks :

PlaceText          Slot_35        “1111”

Et voilà, with a bit of trickery, the obstacle is overcome !

D) Conclusion

Impose files with PDFToolBox is really powerful and simple. Of course, learning SheetConfigs and RunLists syntax has a learning curve. Even the rare limitations can be overcome. Maybe you find more advanced imposition software but keep in mind that PDFToolBox is at first a PDF Preflight and correction software. And yet its imposition engine will cover most of your prepress needs. 

If you want to learn more on Callas PDFToolBox, as we only scratched the surface here, feel free to contact us. If you are interested by IndyFont, visit IndiScripts website.

See you soon.

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