How can you tell the difference between a real movie poster and a reprint?

Well the legitimate copies will say reprint on them. If you want to make sure its a real movie poster the dimensions of the poster will be 27 x 41 so it will fit the markee's. There are other sizes like Half sheets and quads but I figured you were speaking of the standard poster.They make posters 27 x 40 that they usually sell to the public and are excactly the same picture and quality but if you check the movie theater size I'll bet they are 27x 41