27 posters total! 1 each for the following commonly used prefixes/suffixes:
uni/bi/tri (one poster)
im/in/il/ir (one poster)
er/or (meaning "a person who")
er (meaning "more)
I feature a prefix/suffix of the week on a bulletin board. When printing, I print multiple to a page and students have a reference folder they glue them in to help them make words in one of our literacy stations. I use them with third grade and, if you use IRLA, they include all of the white level prefixes/suffixes!