Why is my Bitmap returning null?

Why does illustrator does not export bitmap with registration marks?

• I cant either find a way to export with trim marks. But a new doubt enters in my mind right now. Does a bitmap image really needs them. Or is the print shop in charge of it?

• Answer:

  Save it as a pdf and under 'marks and bleeds' there is an option called trim marks there is also one for registration marks too. Pdf is the best for printing. Printers will want bleed (where the image or artwork goes a bit further out than you want it cut to) and trim marks on it. I've had printers send stuff back because I forgot bleed. Bleed is important because the printer will print it out then use the trim marks to trim it down as you can't print to the very edge of paper.