Although PostScript technology has been widely adopted by the prepress industry, it is not the best choice for digital workflow and CTP printing. Since different applications generate PostScript in so many different ways, PostScript page descriptions can be very complex, and therefore unpredictable. An attempt to build an imposition from pages retrieved from PostScript can consequently be a difficult or even impossible task. On the other hand, PDF files are highly structured and much simpler to process. The Portable Document Format (PDF), the native file format of Adobe Acrobat, was designed to enable users to easily and reliably exchange and view electronic documents independent of the environment in which they were created. Unlike PostScript, PDF files allows retreival of vital information from each document page, such as its contents, fonts, images and other resources. This makes PDF the perfect format for imposition.
Another benefit of using PDF is size. A PDF file can be compressed, and because of its structure all resources, including fonts and images, can be shared among different pages. This means that a PDF document can be much smaller than an equivalent PostScript code. This feature is particularly useful in the imposition process. The key point of PDF workflow is to keep the PDF format of a document until RIPing. Many imposition programs can import PDF files, but usually they produce only a PostScript output - which means that all benefits of PDF are lost at this point. A simple example can be a step and repeat flat work with a 20MB image on each copy. If the page is repeated on the imposition 20 times the PostScript output would grow to 400MB. In contrast, a PDF imposition would sill have only around 20MB because the image, attached only once, is shared among all repeated pages.
When working with imposition, keep in mind that even PDF files can become so big that handling and viewing imposed documents can be impossible because of time needed to transfer data and refresh a view. The Open Prepress Interface (OPI) should then be used for smooth processing of the data. If you plan to use PDF Organizer with large files, you should include in your workflow an OPI server such as Merge-It which handles PDF files. The MergeIt OPI server, when working with PDF files, optimizes image inclusion. With this method all multi-referenced images will be included only once. The workflow can be extended with in-RIP trapping and color management.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.