There is no denying that PDF is a reliable format for creating and archiving text documents. But there is also another format known as PDF/A. It is widely used in business and has an advantage over other archiving formats in terms of preserving text, vector graphics, bitmap images, and related metadata. Given that PDF/A is an integral part of PDF, we can speak of it as the successor to PDF. In this article, we will look at all aspects of PDF/A, including its types, differences from PDF, and advantages.
Table of Contents
- What is PDF/A?
- Different levels of PDF/A compliance
- What are the different types of PDF/A?
What is PDF/A?
PDF/A is the ISO-standardized version of Portable Document Format (PDF) for archiving and storing electronic documents. The way PDF/A differs from PDF is that it forbids features like encryption and font linking that are inappropriate for long-term preservation. Guidelines for color management, assistance with embedded typefaces, and a user interface for reading embedded annotations are all standards set down by ISO for PDF/A file viewers.
Regardless of the program used, PDF/A is a variant of the PDF format that offers accurate document reproduction. In essence, the file contains all the information required to display the document and all of its features consistently over time, keeping your materials safe, accessible, and protected.
The main driving force behind the development of PDFA/A was to meet the needs of long-term archiving. The standard ensures that archive files can be opened even after a long period.
This format is now commonly used in all industries. According to the information provided by this standard, PDF/A viewers, such as Adobe Acrobat Reader, ensure that files saved in this format can be opened even in the future.
Different levels of PDF/A compliance
Level b (Basic)
PDF/A-1b, PDF/A-2b, PDF/A-3b
The B-level conformance standard is the simplest to meet because it merely asks that documents follow recommendations for trustworthy viewing.
Level a (Accessible)
PDF/A-1a, PDF/A-2a, PDF/A-3a
Accessible compliance is a superset of Level b compliance. It adds requirements for information designed to preserve a document’s logical structure, semantic content, and natural reading order.
A-level compliance not only ensures that documents will look the same in the future but also makes it easier for machines and people to interpret and reuse their content. A legitimate PDF/A will contain material that is better readable by screen readers for the blind, as well as text that can be reliably searched and copied.
Level u (Unicode)
Compliance with level u necessitates the display of characters in Unicode, just like “level a.” This does, however, eliminate level requirements, including the inherent logical structure.
Because of this, a PDF/A that complies with u-level standards will have content that can be reliably searched for and copied, but the reading order will not be ensured.
What are the different types of PDF/A?
PDF/A comes in many possible variants, created by mixing different PDF/A standards and compliance levels. Each PDF/A standard specifies a collection of tools and techniques for image compression that can be used to protect the file’s content. Different compliance levels are supported by each PDF/A standard in turn (a and b for PDF/A-1 and a, b and u for PDF/A-2 and -3). These compliance levels regulate the file’s “accessibility” standards, which have an impact on how easily people and computers can interpret the content.
PDF/A was adopted as an ISO standard in October 2005. It has been continually improved since then, and several more standards have been developed over time. The application offers the user three choices for saving to PDF/A:
Option #1: PDF/A-1b – is the original PDF/A standard, the most commonly used today and the most rigorous. Because it is based on an older PDF standard, PDF 1.4, published by Adobe Systems in 2001, PDF/A-1 does not support JPEG 2000, layers, and attachments. In addition, despite the support in PDF 1.4, transparency was considered “too new” at the time of PDF/A-1’s creation and therefore was not included.
This certification, PDF/A-1b, ensures that a PDF can be shown and read on a computer monitor but does not guarantee that the text will be legible.
Although text legibility is not guaranteed, this certification ensures that the PDF file can be shown and read on a computer monitor.
Option #2: PDF/A-2b – is a strict subset of the ISO PDF specification used to create archival versions of documents with the intent that they will always render the same as when they were saved.
If you wish to produce an archived version of the document and its elements that will always display exactly as when you save the document, save it as a PDF/A-2b file.
Option #3: PDF/A -2u. Level “u” has also been introduced in PDF/A-2. Level u allows organizations to guarantee reliable retrieval and copying of document text without the need for the file to meet another level’s requirements.
The “u” in PDF/A-2u stands for Unicode and enables businesses to guarantee that the document text can be accurately searched for and copied.
Different levels of archiving are offered by each choice, making it simpler to maintain various aspects in your digital file and supporting things like effects and layers.
PDF/A is a subset of PDF designed for archiving information. To keep the information in the file and ensure that the content looks good even after very long storage, PDF/A sets stricter standards than those used in PDF. The most basic requirements of PDF/A are as follows: All content is embedded – fonts, colors, text, images, and no audio/video. The file is not encrypted.
You can read about what an PDF is and how to work with it in our previous blog post.