PDF Requirement

The PDF's original source must be the highest quality and as accessible as possible prior to being turned into a PDF.

There are a number of accessibility issues that can and should be addressed prior to the creation of a PDF. Of those the following are the most common issues that should be addressed before the PDF is created because Adobe Acrobat may not have an easy way to fix these accessibility issues.

Font and Text Alignment

Text Resources:

Text Additional Reading

Blurred sample text in different formats and font families

Readability for persons with visual and reading impairments can be significantly impacted by our font and format choices.

Adobe Acrobat has some limited text editing capabilities but they are best for making minor adjustments. As such, it is better to meet the following before the document is made into a PDF.

Use san serif fonts for copy/body text in PDFs as the stroke width variance and serifs or "feet" on serif fonts can be difficult for persons with reading disabilities to read.
In general, do not use font sizes smaller than 12pt so that your audience may be able to read the text comfortably.
Use bold to create emphasis, reserve italics for citations, and reserve underlines for links. Italics can be difficult to read, especially for those with reading disabilities and underlines on unlinked text can cause unnecessary confusion.
Avoid using ALL CAPS as they can make reading disability symptoms worse and interfere with text-to-speech programs' ability to correctly pronounce words.
Left align text and avoid using two spaces between sentences whenever possible. Center alignment makes it difficult for persons with visual impairments who use magnification technology to find the start of each line. Justified alignment and two spaces between sentences can create what are called "rivers of space" that can make it difficult for persons with reading disabilities to read. WCAG 1.4.8

*Note: With the exception of the final criterion in this list, the above list was made from best practices suggested by sources linked in our Additional Readings page. There are no WCAG requirements that say you must meet these criteria, which means we can only recommend these practices. Please note too that WCAG 1.4.8 is a AAA criteria, meaning it is not always possible to meet this criteria and is thus not required either.

Color and Sensory Characteristics

Sensory Resources:

Color and Sensory Characteristics Additional Reading

Model of how persons with colorblindness perceive color

Image from Wikimedia Commons. Used with Public Domain license.

Around 92% of the population has normal vision. About 4% have red-green colorblindness, which replaces the reds and greens with shades of yellow/brown. Less than 1% of the population has blue-yellow colorblindness which causes their color spectrum to have more cyans and magentas. Less than 0.0001% are completely colorblind, meaning everything is in shades of gray.

Adobe Acrobat may have some means of addressing accessibility issues related to color and sensory characteristics, but it is even more limited than the capabilities associated with font and text alignment. As such, it is important to get the following right before the document is turned into a PDF.

Avoid using only shape, size, location, and/or color to convey importance or information as text-to-speech programs do not verbalize these conditions. WCAG 1.4.1, WCAG 1.3.3
(example: Avoid directions like "Click the small yellow triangle in the bottom corner," unless you give each shape on the page appropriate alt text.)
(Generally not applicable, but too important to not mention) Avoid using only sound to convey information or importance so that those with hearing impairments do not miss out. WCAG 1.3.3
(example: Avoid directions like "Click the button only when you hear the beep," unless you give a visual cue at the same time as the beep.)
Use appropriate color contrast so that those with colorblindness might be able to read the text as well. WCAG 1.4.3
(We recommend using a color contrast analyzing tool when meeting this criteria. Paciello's Colour Contrast Analyser is a particular favorite of ours as it has a handy eyedropper tool for identifying colors. When using this tool, you only need to pass the AA requirement for either small or large text. Large text is considered $LaTeX: \ge14$ pt if bold and $LaTeX: \ge18$ pt if not bold.)
(Recommended) Avoid using pure black text on white backgrounds or vice versa as it reportedly can aggravate dyslexia symptoms.

For the color contrast criteria, we recommend using Paciello's Colour Contrast Analyser which has a handy eyedropper tool for identifying colors.

Math and Science Notations

Math Resources:

Math Additional Reading

Accessible Math on the Web: Part 2, The Simple Way with MathML and HTML5

When documents contain equations or notations that are more complex than than what you can type with your keyboard's number pad, it is recommended that the document's contents be stored as a web page or Word Document instead of a PDF. This is because text-to-speech or screen reader programs will not read mathematical notations correctly if the equations are not written with a programming language called MathML and it is not possible to write or correct MathML equations within Adobe Acrobat.

If you must store the document as a PDF, be sure that the equations are written with the MathML programming language before the document is converted to a PDF (WCAG 1.3.1, WCAG 1.3.1 (G115)). Within Microsoft Word, it is possible to do this with the help of a plugin called MathType. At this time, only those in the college of Engineering and Science can get MathType through CCIT. For everyone else, the free trial on Design Science's website is another good option. When the trial expires, the program goes into a lite mode which removes the most advanced equation and notation creation capabilities while still allowing the most common notation capabilities.

If you have a PDF but do not have the Word or InDesign file that was used to create it, it is possible to convert the document to a Word file, use MathType to make MathML notations, and convert it back to a PDF. The only drawback to this method is that documents with complex layout may experience undesired shifts in element placement. If the shifts are drastic enough, it may be appropriate to turn the equations in the original document into images and add alt text (see the Graphics portion of this guide for more information on how to do this). This said, it is preferred that a different, accessible resource be used instead.

If you work with math and science notations often, we strongly recommend learning more information about Math Accessibility through the resources listed in our Additional Readings page.

*Note: Due to technological advances, it is increasingly possible to write math in LaTeX and have it be considered accessible (especially if your audience is expected to be proficient at writing LaTeX code). But, when it comes to PDFs, LaTeX has the same problems as MathML.

Animation, Video, and Audio

Media Resources:

As PDFs advance, it may be possible to play animated GIFs, Videos, and Audio within the document. Even if this becomes possible, we generally discourage embedding such elements in PDFs and instead link out to these resources. If, however, you need to embed such elements, be sure that they are accessible before you do (also be sure to include a URL nearby that allows those who print the document to get alternate access to the embedded resources).

Accessible animated GIFs need to be embedded in such a way that the animation can be paused or stopped, or the image can be hidden. This is meant to help those with attention deficit disorders to focus on the information surrounding these images. It is also a way to overcome failures to meet the following point. WCAG 2.2.2
Accessible animated GIFs and Videos need to avoid blink and flash rates that could cause seizures in persons with photosensitive epilepsy. WCAG 2.3.1
Accessible videos with plot-advancing audio (speech or lyrics) need to have captions so persons with hearing impairments can access the video's content. WCAG 1.2.2
Accessible videos without plot-advancing audio should have a transcript or audio descriptions that describes the purely visual information so persons with visual impairments can access the video's visual content. If you go the descriptive transcript route, the transcript can be within the PDF or linked near the video. WCAG 1.2.1, WCAG 1.2.3
Accessible audio files containing speech or lyrics need to have transcripts so persons with hearing impairments can access the audio's content. This transcript can be within the PDF or linked near the audio player. WCAG 1.2.1

Clemson Online has a guide on making video and audio content accessible and they have some Media Accessibility Services that can be used to meet the video and audio requirements.

Also, with the animated GIFs, the following tools may be the best way to meet the first requirement (pause, stop, hide).

Last Updated Fall 2020