The portable document format (PDF) is a specific file format that can store the text of a document along with images, interactive fields, vector graphics, raster images and dynamic content. For many years, the PDF format was the proprietary property of the creators and it was very difficult to make a PDF without using their software. The PDF standard was eventually made open source, and many major word-processing suites soon started to include an option to export documents to the PDF format. There are two stages required to make a PDF file, the first of which is to properly design the document. The second stage requires using software that will convert the document into the PDF format, which can actually be very complex depending on the document contents and the desired quality of the results.
To make a PDF file, the content of the file first needs to be created. Most simply, text can just be typed out in a word-processing program. It also can be as complex as using vector-based publishing software to make exacting layouts according to precisely specified dimensions. In general, it is easiest to create the content in the same program that will be used to create the PDF file. If the program does not have an export-to-PDF option, then the process becomes slightly more difficult.
A third-party program or website can be used to convert a file into a PDF file. There are a number of programs that can convert a document, as well as websites that offer scripts to make the same type of conversion. Very close attention needs to be paid to exactly what file formats the program is able to read and convert. Text-only documents usually are not a problem, although documents with embedded images and those that employ vector graphics to draw charts can present some problems.
There are two methods that a program will used to make a PDF document. A thorough program will actually convert the different parts of a document into proper PDF elements, so text remains text and images are formatted and encoded correctly. Other programs sometimes take shortcuts to make a PDF, and those shortcuts could be one of the only solutions for original documents in unsupported formats. The shortcut method essentially turns a document into a raster image, sometimes through the print function, and then places that image into a hollow PDF file, reducing the quality and scalability of the PDF while dramatically increasing the file size.
Once a PDF file has been generated, it is important to attempt to view the file in several programs, if possible. This is because some formatting cues in a document can translate poorly and wreck any formatting within the PDF. The PDF also should be loaded at least once just to ensure that the conversion or export was successful and did not create a corrupt file.