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Frequently Asked Questions - portable


PDF or Portable Document Format has become almost ubiquitous in modern computing situations. The ease of creating, viewing, and distributing PDF documents make it a versatile and efficient way to move information from person to person, place to place. Unfortunately, PDF for all its virtues still has some limitations and constraints that must be considered.

A recent implementation of the Adobe Acrobat introduced something called the portfolio. A portfolio is a PDF collection of other files. This means that the file is an aggregate of other files collected into one place. Each internal PDF is separate within this portfolio retaining its same structure, format, and appearance. The problem with portfolios is that not everyone can view a PDF portfolio. While most people can easily see regular PDF files, the portfolio causes special problems and may make the entire collection unusable.

Viewing PDF documents

To view a portfolio file, the simplest thing to do is to download the latest Adobe Reader from Adobe (http://get.adobe.com/reader/). Since portfolios are an Adobe invention, their product Reader should properly interpret and present the portfolio for use. Once downloaded and installed, try to view the PDF portfolio and the contents should appear. If they do not, try to save the portfolio files to the hard drive and open it from there using the Adobe Reader program. This is useful when the Acrobat plug in is not working in the browser for whatever reason. Downloading and viewing using the Acrobat program bypasses the plug in altogether.

A second option is to download a third party PDF reader capable of viewing portfolio collections. One such program on Windows is called “Sumatra PDF Reader.” It is a small, fast, and competent PDF viewer able to view portfolio files. Once the main file is opened and the portfolio file is clicked, all PDF content within is displayed.

Creating PDF Documents

To help ensure all parties can view the PDF information, we do not recommend users create portfolio files. In most cases, creating a single PDF of the collective data is preferable. Instead of creating an aggregate file collection of separate PDF documents, the user creates a single PDF that holds only the content of the other PDF documents. There are several ways to accomplish this.

The simplest and most straightforward method is to use whatever program was used to create the PDF (Word, Libreoffice, Excel, etc) and generate the total content placing the output in one file. This may be a multiple page word document saved into a single file. Since it is a single file and not a portfolio, all users should be able to read the content without problems. This also has the benefit of allowing users to control bookmarks, page numbers, and styling information to ensure a consistent appearance.

A second approach is to combine the multiple PDFs into a single PDF file. Programs such as PDFSAM, PDFMerge, and a variety of online tools can take many existing PDF files and generate a single PDF output file. Many are free and free to use. There are several downsides to this approach. Because each file is usually different from the others, there is no consistent formatting information. Fonts and fonts sizes may all be different in each document. Page numbers are likely to start and stop in each document giving the end user several “Page 1”, “Page 2”, etc. This may make navigation within the final document more challenging.

A third approach is to not combine the PDF files at all. Instead, just zip up the folder of documents using a zip program. This zip can then be sent via email. The end user receiving the zip file can unzip it and pull each PDF files from it and use it as normal. Since there is no combining process, all page numbers and formatting should be consistent within the document.


Many PDF files list bookmarks or links to content within the document. Often appearing a a table of contents the bookmarks provide a way for users to navigate to various points within body of information. Not every document has bookmarks but many large document do.

Various tools that manipulate PDF files often dispense with bookmarks preserving the content but not the links for jumping to the content. It is true that a merged document can end up with confusing sets of bookmarks as references between multiple files are all jammed together without regard for the overall context of what goes where. In most circumstances, the bookmarks are useful and keeping them is desirable. The tools listed on this page all preserve bookmarks for files that have them. If any of these tools does not manage bookmarks properly, please let us know.

Software and Tools

Adobe Acrobat (http://www.adobe.com)– the commercial application from Adobe used to create and manipulate PDF documents and content. Not free.

Adobe Acrobat Reader (http://get.adobe.com/reader/) – adobes native tool for reading PDF Files. Free and downloadable, it exists for multiple platforms. It is free.

Sumatra PDF Viewer (http://blog.kowalczyk.info/software/sumatrapdf/free-pdf-reader.html) – Open Source and free, this lightweight PDF reader is fast and capable.

PDFSAM (http://www.pdfsam.org/) – PDF Split and Merge is an Open Source free program used to combine several PDF files into a single PDF result. It makes a single PDF file, not portfolio composites like Acrobat can.

Sejda (http://sejda.com/)– online PDF manipulation website allows various functions to be performed on PDF files. 50MB space limitation.

7-zip (http://www.7-zip.org/) – Open Source free software capable of creating or viewing zip archives and many other archive formats too.