First of all, we want to introduce to you the idea of Generic Font Family. A generic font family is a group of font families with a similar look. There are five generic font families defined in today's web technology: serif, sans-serif, cursive, fantasy, and monospace. While serif fonts have small lines at the ends on some characters, sans-serif fonts (where "sans" means without) do not have the lines at the ends of characters. For the purpose of research poster design, we recommend using only serif and sans-serif fonts.
Verdana vs. Garamond
For the title, consider using a large, bold san-serif font, such as Arial Black, Fanklin Gothic Heavy, Tahoma, Trebuchet, or Verdana. Make the font size between 72-120 points.
For the subtitles (authors' name, school name, etc.), use the same font as your title but make the font size smaller than the title. A font size between 48-80 points usually work best.
For the section headers (abstract, introduction, results, etc.), use the same font as your title and subtitle. Make the font size approximately 50% larger than the body text, betwee, 36-72 points. Make sure that all section headers are the same font size.
For the body text choose a serif type that is very readable, like Garamond, Book Antigua or Bookman Old Style. Make the font size between 24-48 points. Make sure that the body text is the same font throughout the entire posters.
DO NOT USE ALL CAPITAL for any portion of your poster. It is harder to read and it looks like you are shouting. Finally, use familiar fonts so that it will be easier for your audience to read.