That's not Qimage's media size list: it is the driver's list.  If you don't see A3+ then the driver doesn't have that size available under the current settings.  If you open the driver settings using the "Properties" button, you can go into the driver and see why that size is not available.  Sometimes it is due to the media type chosen.  Other times it is another setting such as borderless, the output tray selection, or another selection that is preventing you from selecting that size.  But reviewing the settings in the driver dialog should tell you what the limiting factor(s) is/are.

Regards,
Mike

Thank you Mike

I've been off line and I will see whats up with the printer drivers and I'll be sure to get the latest Canon updates