User Activity

When I try to print photo's and get the box to set up the printer. Chose paper size and a lot of weird sizes come up with no explantion of what they mean. What is a3, a4 ect?
Anybody know about what it cost's per sq inch for ink for photo printing?
Anybody know if Canon might have a 13x44 printer? Love my 9000 MKII but only goes to 19".