Although there are no absolute answers or guidelines for accessibility that will guarantee equal access for everyone, below are several accessibility considerations to take into account when designing academic posters.

Colors

• Ensure sufficient contrast between the text and the background using a tool such as Colour Contrast Analyser or WebAIM Contrast Checker.

• Avoid relying solely on color to convey meaning. Instead, use patterns or shading in addition to color on charts, graphs, illustrations, and maps where color differences are intended to convey information.

Fonts

• Recommended: Sans-serif fonts such as Arial, Gill Sans, Helvetica, and Verdana for body and heading text

• Serif fonts such as Times New Roman and Garamond are recommend for headings only

Text size: bigger is better!

• Main title: 72 point (minimum) - 158 point (ideal)

• Section headings: 42 point (minimum) - 56 point (ideal)

• Body text: 24 point (minimum) - 36 point (ideal)

• Captions: 18 point (minimum) - 24 point (ideal)

Digital formats

​If the poster will be available in a digital format (e.g., as a PDF posted on a website) it is important to ensure that the poster is accessible to people using screen readers.

• Provide alt text and/or descriptive captions for images, figures, and charts.

• Define reading order for blocks of text and other poster elements: in PowerPoint, go to Arrange → Selection Pane → Drag items into the correct order (note that screen reader will read from bottom to top).

• PowerPoint has a built in accessibility checker that will highlight issues and tell you how to fix them: Tools → Check Accessibility → Inspection Results

• If exporting to PDF format, be sure to “Save to PDF” or “Save as Adobe PDF” (not “Print to PDF”).

• Guidelines for Creating Accessible Printed Posters 
  More detailed guidelines for “creating the most accessible poster presentations possible”
   
• Coloring for Colorblindness (David Nichols)
  A great place to start your reading if you’re not sure what color choices on a poster have to do with accessibility.
   
• Colour Contrast Analyser
  Downloadable application that helps you determine the legibility of text and the contrast of visual elements, such as graphical controls and visual indicators.
   
• WebAIM Contrast Checker
  Another free online tool that can help you ensure that text will be readable.
   
• Yale Web Accessibility - PDFs and Documents
  If your poster will be available in a digital format as a PowerPoint slide or PDF, review these tips and tricks about how to ensure that your poster is accessible to those using screen readers. Particularly important for academic posters are slides about alt text and reading order.