In the Microsoft world you're able to print what is called a Poster Print, the whole picture covers an area of four A4s. When printed out part of the picture is printed out on each piece of A4 you then trim the edges and tape them together and get the full picture. d.
I don't think there is similar functionality on a Mac built-in. I found this software though - free, but not sure if it's what you're looking for.