I'm using QU to try to print 4.25 x 5.5 note cards. I have in Photoshop two-up on a canvas size of 8.153 x 10.253.

QU won't let me print that on one page unless it reduces the image to fit on one page.

In QU I have chosen Media size as 8.5 x 11 and I have in Prints > Custom (Special Sizes) Use ORIGINAL/embedded size. Original size is set to 300 PPI, same as the document in Photoshop.

In an attempt to remedy the issue, I reduced the canvas size slightly. While that got me closer (judging by a reduction from 306 to 305 PPI as reported when hovering over the preview image), I would have had to reduce the canvas size more than would seem practical to satisfy the Confirm dialog.

I am not trying to print full bleed. I successfully printed exactly one-half this size (one-up on a 5.5 x 8.5 sheet) as a test so I don't understand why twice the size did not work.

Would it work to set Sizing Method to BORDERLESS even though I'm not actually wanting a borderless print?

Thank you for your reply, Fred A.

I don't understand how it works if I tell Qimage that I want 4.25 x 5.25. I need to use one sheet of 8.5 x 11 paper to make two 4.25 x 5.5 note cards - one card folded requires paper 8.5 x 5.5.

And why did the 8.5 x 5.5 test work fine (for one card) but when I expanded the canvas to fit two-up, it did not work?

Because Qimage knows it can rotate one 8.5 x 5.5 print 90 degrees to align the 8.5 inch side with the 11 inch side of the paper.  If you try to print two 8.5 x 5.5 prints, that requires 8.5 x 11 inches which, if you are using 8.5 x 11 paper, requires that you set borderless in the driver in order to get both to fit on one page.

One thing confuses me.  You said "I have in Photoshop two-up on a canvas size of 8.153 x 10.253".  What are you accomplishing there, and why such an oddball canvas size?  You can't fit two 8.5 x 5.5 prints on an 8.153 x 10.253 canvas.  So I'm not sure what you are doing in Photoshop (and why).

Regards,
Mike