The time we did a poster session at SENYCon in 2015
Formal definition from Wikipedia: A poster presentation, at a congress or conference with an academic or professional focus, is the presentation of research information in the form of a paper poster that conference participants may view. A poster session is an event at which many such posters are presented. Poster sessions are particularly prominent at scientific conferences such as medical and engineering congresses.
For our purposes: Any stand-up display that tells a story about your library or project. It should speak for itself if someone is not present to discuss the poster. When you are there to speak about it, you can explain the context of the poster and answer any questions the participants might have.
The poster can be designed on the computer and printed in one go or can be a series of printed items pasted to a stand-up cardboard tri-fold. They can be displayed on tabletops or easels.
DO: Make certain your poster stands on a flat surface or that you have an easel to hold it up.
Don't: Assume that the venue will have tape or tacks or a way to hold it up on the wall.
DO: Write a short, precise title on the top of your poster
Don't: Make viewers guess the subject of your poster.
DO: Use as few words as possible. Viewers should get the gist of your poster within a few seconds.
Don't Fill the space with small, hard-to-read text. If you need to elaborate on items, you'll be there in person to go into detail. If you're feeling stuck, you could always include a URL or QR code that leads to a webpage with more information.
DO: Remember to give yourself credit and to include the name of your organization!
Don't: leave people wondering who made the poster.
DO: Make certain your poster can be read from far away. Use the best printer you have. Choose to use BIG FONT SIZE and
Don't: go wild with hard-to-read fonts, monotypes, or small sizes, or switch fonts within the same poster.
DO: Layout the poster in a logical order. (People tend to start reading vertically and then move from left to right.)
Don't: make the viewer's eye jump all over the place to figure out the story.
DO: Bring supporting materials. If you have swag, props, or examples of your work that fit on a tabletop, bring them! Do be clear if the swag is a giveaway by including a "take one" sign.
Don't: Let your supporting materials steal the show by overdoing it with glitz.