The paper size option will provide all the supported paper sizes for the model you have. If there is no paper size to match your settings, it means it can't print them. However, instead of choosing the correct one, just use an international format A4, A5, A2, A3 (depending on your printer) and then cut it with a cutter and that's it. It's the easiest way to solve this problem when the printer doesn't have support for a certain paper size.