Art Work for Exhibit

I can not remember and I can not find it anywhere in my notes but do we have to mount our piece? Mine is 11" x 23" before any mounting, do I need to mount it or just bring it the way that it is? If I need to frame it that is not a problem but I need to know so I can get that taken care of soon. I know that the finished piece can not be any bigger than 18" x 24" but is that before mounting or just the art work?