In some ways, clarity is the overall result of good content and design – and is your gift to the audience, in a busy setting rife with information overload. But there are some specific tips to achieve clarity, which will be appreciated. Cut text wherever you can, and then go back and try to cut even more.
One of the most common complaints about conference posters is that they do not include enough “white space”, or parts of the poster with no text and no graphics. On the flip side, good use of white space is one of the first things you will notice about a well-designed poster. White space is as important as the information on your poster, because it allows your viewer to focus on important content (quality) and makes the amount of content (quantity) seem manageable. Make sure you have enough space between columns and paragraphs. Increase the line spacing if it helps give “breathing room” to the poster. If you have a large graphic, allow enough room around it so that it does not look crowded.
Use bullets anywhere you can because you can use fewer words, and this format organizes the material into clear messages.
Reduce the number of words wherever possible. Left-justify your text to allow a “ragged right” edge, which is easy for the eye to follow (this paragraph is left-justified with a ragged right edge, for example); or you can fully justify your text, so that it looks like a block (this is commonly used in newspaper columns, for example). Use plain language to convey information, except where technical language is required. Limit the use of jargon. The style you would use for a peer-reviewed journal or a research paper is not the same writing style for a poster which should be understandable to someone who is not familiar with your content area.
Captions for photos or graphics are a nice trick for getting more information in your poster without taking more space or looking too busy. Alternatively, if you have too much text on your poster, can you convey some of it through captions? Captions can be written in a small font with tighter line spacing. You can also try making the type color a bit lighter, such as a dark gray, which is still readable but is less busy. Information that is conveyed through graphics should not repeat any other information on the poster.