Is it an acceptable practice to use simple graphics found on Wikipedia (and hence in Wikimedia Commons) in a conference poster?
From the legal point of view, this seems to be fine, as long as the image is properly attributed. Presumably it should suffice to mention the source in acknowledgements section. Or am I missing something?
How would this be perceived? Would it come across as unprofessional? The poster I am preparing is for an interdisciplinary and not too formal event, and the graphic I'd like to add is meant to illustrate a basic mathematical notion. (However, more general answers are very welcome.)