We printed a scientific poster this morning that uses what’s known in the graphic design field as an “open” type face or font. It’s when the type isn’t solid.
First of all, open face type can be just plain hard to read. Your eye likes something distinct and solid to read, in part because that’s what it is used to seeing. Open face type is really designed for fanciful things like greeting cards, where only a few words are used. You can get away with “Congratulations” in an open type face, but it makes a lousy title for a poster and it’s even worse if used in the text body of a poster.
The other problem with open face types is contrast. Since you don’t have a big solid letter, you lose the strength of it. If the color of the type is something other than black, and the background is something other than white, things can get really hard to read.
So do yourself a favor. Use Arial for titles, and Times New Roman for the body text. Use Symbol for your Greek letters. And forget the open type faces on your research poster. Your goal in producing a research poster is to share information, not create a fanciful work of art.