Acrobat PDF

What is PDF?

The PDF abbreviation means Portable Document Format. This type of files can be read and printed using a free viewer, the Adobe Acrobat Reader, or other free readers like Ghostscript and Foxit. The free reader is included with many commercial applications, in CD-roms of magazines and, in any case, it can be downloaded for free from its publisher (www.adobe.com.) PDF is a very common file format, very used in the Internet and in the manuals from many programs. In fact, some programs no longer include printed help; they enclose a manual in a PDF file, so that the user can read and print the sections that really interest him. Many official and company documents and forms are also provided digitally as PDF.Which are the reasons of this success? What advantages does this document format have? In this article we will explain these questions.

Acrobat Reader lets you read the document, to print them and to search for words or expressions. Normally, parts of the text and the images can be copied to other applications (unless this option is blocked: the Acrobat files of can be protected against modification and/or copy.) Sometimes, the document includes a table of contents and thumbnails which appear in the left margin of the screen. Pressing on a title of a section works like an hyperlink. Thumbnails are especially useful for image-rich documents. You can use different zoom levels in the program, with the usual magnifying glass tool and hand tool to move the visible area.

Within the document itself, we find text and images, and hyperlinks similar to those in a web page; they can link to any type of digital document, web pages included. The PDF documents are important especially due to the fact that they keep faithfully the layout that the designer created, and all the details of the design as colours, typography, vectorial shapes and photography, independently from the operating system. Unlike web pages, all these aspects are not alterable by the preferences of the user. In addition if a PDF file contains vectorial artwork, it will not lose quality when increasing the magnification. And to round things up, PDFs contrary to popular belief, can be highly accessible documents!

Many of the singular characteristics of the PDF format owe their magic to the code used to generate a document, based on PostScript, a programming language originally designed for the page definition in high resolution printing systems. A PDF file can be output with many different possible settings, optimizing its size according to its destination: press, electronic distribution and Internet, a CD-ROM or multimedia... Being a variant, then, of the PostScript code, PDF files can include vectorial graphics, with all their advantages.

The fonts used in the document can be embedded to avoid display problems. If the user doesn’t have the font you choose installed, the PDF includes it, so every reader will see exactly what you intended. There’s a side effect of embedding fonts: the size of file increases in proportion to the number of embedded fonts, but this is a small price to pay if we are sure that all the typesetting attributes of the document will be kept intact. In order to avoid that the size increases too much, Acrobat allows to embed only a subset of the characters, with the minimal necessary information to draw in screen only those characters that actually appear in the document. The most trouble-free fonts for embedding are, not surprisingly, Type 1 fonts: it is not necessary that they are even installed in the system, it’s is sufficient that they are activated (loaded in memory) at the moment you create the PDF.

How to create PDF files.

The best solution to publish digitally in Acrobat-PDF is, naturally, to have the specific program from Adobe: the Acrobat suite. This is a commercial program and you will consider this option only if you generate a great amount of projects. Other alternatives include free programs like Ghostscript and others, such as PDF995. Acrobat is a package that includes different utilities to create and modify PDF documents. The key piece is a program with a interface similar to Acrobat Reader, but with more options to edit the contents, to add to indexes and thumbnails, and other options. Acrobat Distiller and PDF writer , also part of Acrobat, work like printers of your system. When you have a ready document in any application, you print it as a PDF, choosing as printing device either the Distiller of the PDF Writer (or any other PDF generating utility you have installed.) Instead of printing physically, these programs generate the necessary PostScript code for the PDF file.

The PDF Writer utility is simpler in its handling. It is also somehow limited and not so robust as the Distiller. For example, it does allow to embed fonts, but tends to fail more, and it doesn’t allow vectorial shapes from EPS. Distiller admits more configuration parameters and finds the Type 1 fonts better for their automatic embedding in the document. You only have to point them to the folders of the system where the fonts reside, and it will gather the ones that are needed in a project.

PDF resources

Adobe Systems is the developer of the PDF format and the PostScript language. We can download for free the last version of Acrobat reader and obtain general data and suggestions on PDF use. From Paper to Web is a very interesting manual about digital document creation published by Adobe Press. A good book that can could be downloaded for free, in format PDF, naturally, from the Adobe Press website. It is was a good gift (the book cost 45 dollars.)

Pure PDF, PDF Planet and PDF Universe webs dedicated to everything related to PDF that offer, among other things, interesting ideas, links and programs related to the creation and manipulation of Acrobat files.

Octavo is a very particular publisher. A magnificent example of the applications of the new technologies, and the unsuspected connection between the future and the past. They reissue old book editions digitally - works that are very valuable as collector’s items. They use the PDF format to reproduce the images, the typography, the texture of the paper... but on the other hand the text and the images are completely editable (they are possible to be copied, to search words...) and they include an index with hyperlinks and thumbnails. Fascinating. These editions are sold as compact disc, with a reasonable price, at least in comparison with which it would cost, for example, the princeps edition of De Humani Corporis Fabrica by Andreas Vesalius. In its website we find free samples from its books and they explain in detail the process of production of their products. A mandatory visit.

Ideas for PDF.

When and how to use it

The Portable documents are thought for the electronic distribution of files, through a network, in CD-ROM or other supports. The archives keep faithfully their original design, as we have commented. Which are the advantages over a web page? Until versions 4 and later of the browsers appeared, the advantages of format PDF over the web pages were much more evident; in the first versions of the navigators, to begin with, it was not possible to assure that the reader would see the page with the size, colour and font chosen by the designer; and the possibilities of page layout were frankly limited. In the early 90s, it wasn’t possible to distribute the text in columns, the main layout system of most publications. There were no way of getting the wanted fonts on the pages, and the graphics had to be bitmaps (GIF and, later, also JPG.) All of this gave a clear edge to the Acrobat files as an ideal format to distribute documents in format identical to the original, and with much more flexibility.

These last years, nevertheless, with the latest versions of standards-compliant browsers, the situation has changed totally, and the distance between both formats has narrowed. Now a web page can be designed with a great flexibility; the fonts can be more carefully selected and typeset, and they can even be embedded in the document; compact vectorial interactive graphics can be added (Flash and SVG) and the idea of the designer can be achieved more faithfully. Even so some problems arise from the lack of control of the physical size of the pages when printing, the correct positioning of the elements, and other questions that take to us again to the necessity of a format like the PDF, that offers all the guarantees of an absolute consistency between the original document and the one that the reader sees in screen or printed. Unlike wih web pages, with Acrobat normally you need no plugins or a specific version, or a certain configuration. On the other hand, when you transfer or download a PDF file, the information is packed in a single file instead of being distributed in several archives, and perhaps folders, as it is the case of the web pages. Furthermore, the font embedding process in web pages has been until now a process without guarantees and, in the best cases, quite time consuming, while if you create a PDF document with embedded fonts, the program does it automatically and usually without problems.

In the world of printing, the PDF format has occupied another field of application: many designers now create Acrobat files to hand out to the print service. If the output of the Acrobat file is properly specified, the printer will have everything that it needs to be able to correctly print the design that has been provided to him. In the offices, the PDF document generation helps to reduce to the amount of forms and other documents and paperwork that must be stored and filed.

Advice and interesting examples of the pdf use.

Some examples of the use of PDF.

Let’s see some applications for which the PDF format is ideal: these are simply a few real examples; there are many more ways of taking advantage of it.

Forms. To electronically distribute a form that is scrupulously preserved in its layout, PDF is one excellent solution. Many institutions, among them regional governments or State legislation publications, publish an electronic version of their issues and they distribute it in form of CD-ROM or through the net. Thus, a citizen who, for example, needs a specifi form, can download it from the Internet, saving the trip to an the administration buildings to get it. With Acrobat, the company or the administration makes sure that the form that is printed will be identical to the official model
E-books like the ones of the fascinating Octavo project, that we have commented already. It is fascinating how the past cultural heritage can be recovered, in a wonderful combination of the world of paper print and the world of digital bits. Now the e-books are becoming more and more common, an electronic book format where still there is much to decide, and where it seems that a format as the PDF has many possibilities of becoming a standard, or at least succeed.
Publish an ezine. If we want to publish an electronic magazine, ezine, the simplest way is to make it is as a web page, and ideally a blog, if it will contain frequent updates, multiple authors or discussion of topics with the visitors. But for more static publications, or design-intensive ezines, if the format has special importance, the typography must be finely set... we can use Acrobat. There are many excellent examples of the use of PDF for catalogues, magazines and other related applications. Check out the past issues of Adobe Magazine, for example, or the catalogues from Veer (especially the “Activity Books”.)
Presentations and educational material for screen projection. Acrobat can be an excellent tool for the creation of presentations, similar to the popular PowerPoint. It has a series of clear advantages: the control of the transition between pages, links, flexibility in the incorporation of graphics and fonts, layout fidelity... and especially the embedded vector graphics are zoomable with no loss of quality. In addition, you can prepare your presentation in any application, and later create the PDF.
Print-oriented workflow; otro ejemplo citado antes. Dado que PDF está basado en el lenguaje estándar de la impresión comercial de calidad, el PostScript, y que las fuentes Type1 también están basadas en PostScript, se trata de un formato fiable, respaldado Since PDF is based on the standard language of the high-end commercial printing, PostScript (Type1 fonts are also based on PostScript) it’s a reliable format for the exchange of graphical documents in a professional production workflow, endorsed by a long experience of professional use. Using the PDF/X especification, a subset of the PDF format, designed to eliminate many of issues with the colour, trapping and font variables that lead to printing problems, it’s possible to get reliable delivery of press-ready, high-end designs.
Catalogues. Especially in the case of graphics or fonts, many websites provide catalogues of their products in PDF. The visitor saves time because he doesn’t need to browse different sections of the website to see the different products. He downloads a single file or a few files and then he can examine them in detail, even offline. Again, there is a number of distinct advantages regarding layout, vector graphics and fonts.
Compilate a number of web pages in a single file.. A good way to transport a set of pages in HTML. This is a good idea, for example, to create an offline presentation from a website. It’s enough to create an single file in PDF, which will include all the text and the images. The Acrobat program easily does it, with its Web capture option. It even has the capacity (like programs like WebReaper or HTTrack) to download a whole Website, or the parts that we indicate, and to follow external links to, next, create a single document. The freeware program HTMLDoc and others can do something similar.