Increasing font size isn’t enough to ensure accessibility
Large print—also known as large-font or large-type—refers to formatting a textual document whose font size is significantly bigger than the 12 points most commonly used in printed media and digital documents. The font size of the large print is usually at least 18 points, which is equivalent to 24px for a web CSS font size.
Note that the term ‘large print’ often refers to larger than regular font size, but that is not necessarily accurate. For example, according to the American Publishing House for the Blind, the average font size for the body of a printed document is 12 points, enlarged print is 14-16 points, and 18 points and above is considered large print.
Not all people who are legally blind have sufficient vision to read text, even if the font size is larger than normal.Are large print documents inherently accessible?
If a person is completely blind, the large print won’t help. Correct tagging, among other accessibility features, also needs to be in place if the document they are reading is a digital PDF.
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Large print may aid readability for people who are partially blind. However, readability is not equal to accessibility. For those with low vision, font size is only one of the features they need. Additional attributes are necessary to make textual information fully accessible.
Some font styles aid readability and, therefore, enhance the accessibility of textual information. For example, according to the guidelines developed by the American Printing House, sans-serif fonts (like Verdana, Tahoma, and Helvetica) generally are easier to read.
The amount of white space in a document plays a significant role in determining how easy or difficult it is to read—breaking up the text and making reading easier.
Think how difficult it would be to read a text block with 20 sentences and no line breaks instead of five paragraphs with four sentences. White space not only helps with readability, but it is also more aesthetically pleasing for those who can see it.
As a general rule of thumb, websites and apps should not use color as the only way of conveying information, indicating an action, or prompting a response. For instance, users with color blindness or visual impairments might not be able to read the information.
In addition to color, you should not use a font, style, or format as the only means to convey information. This applies even if the document is in all black and white text.
For example, when showing a bar chart, each column should have a different pattern in addition to a different color.
The text and background must also comply with WCAG rules on color and contrast. The article, Best Practices for Color and Contrast for Digital Accessibilityprovides detailed information.
It’s best to avoid or limit the usage of all-caps in text. Similarly, using too many bold sentences is also not a good authoring practice.
All in all, large print certainly aids in enhancing the readability of textual information in a document; however, just blowing up the font size of a badly authored or formatted document won’t make it more accessible.