All three (Qimage, LR, and PS) use the same driver so it's down to driver settings and print size.  In Qimage, the setup to get a borderless print (regardless of paper size) is:

- Make sure the crop button (scissors icon on the Prints tab) is ON
- In the driver properties, select borderless and set your "Amount of extension" in the driver's Page Setup tab
- Add the print using the "Fit to Page" print size

Regards,
Mike

If you click the "Properties" button on the Printers and Settings tab to open the driver, then click on the Page Setup tab at the top of the driver, you'll see the Amount of extension slider.  The more you slide it to the right, the more the print will be extended beyond the edges of the paper.  Extending the print beyond the edges of the paper prevents thin white slivers from appearing at the edges of the paper (due to slight inaccuracies in the paper loading mechanism) but also prints a little ink onto the sponge in the printer.

Regards,,
Mike