The paper may be larger than the actual print size you desire, thus it varies. If you want a 16 x 20 print than using paper that is sized 17 x 22 would be fine, assuming you could find that size paper from a paper company and your printer could print to that size. There are a lot of variables in printing. You need to consider if you are going to mat the print, which I would recommend and perhaps if you were going to leave a small white space between the print end and the mat itself and what size frame you wanted to use. So, lots of choices. I print most of my own work, generally no larger than 10 x 15 or 12 x 18, digital sizing, and would put the 10 x 15 matted into a 16 x 20 frame and the 12 x 18 matted into an 18 x 24 frame. I use paper from Epson and Red River and use both 11 x 17 and 13 x 19 sizes. There are many other choices, too, based on what you want. Determine your goal and work out from that point to find out how to achieve it.