For text use a non serif type face, such as Helvetica. It is much easier to read. Don't put too much text on slides or other visuals. It is difficult for non-native speakers to read quickly. Whenever possible, use an image or diagram to make a point or explain a concept.
Images are generally more easily understood by all language groups.
The posters may be presented in French, English and Spanish. Each poster presenter will be assigned display board. The board will have a mountable surface of about 90 cm long and 180 high. Tape is not to be used on the surface, and pins will be provided. You are expected to attend your poster for at least two hours.