Print size vs. paper size

[Edwa]

What setting do I need to choose to print a photo cropped to 11x14" in Affinity (so it will fit into that size mat opening) and printing to 13x19 paper. 

I set the printer  properties to the paper size (13x19) and print  the cropped photo but instead of 11x14  the print fills the entire 13'' space with 1.5" borders on the other two sides.

The Help Manual says:

in the Show Details of the dialog):

• Actual Size—the project's current image and canvas size is honored.
• Scale to Fit—the image is temporarily scaled to fill the selected page size with no cropping taking place.
• Scale—the image is printed at the temporary scale set in the adjacent input box.

'I chose Scale, but I don't know what "the adjacent input box is" and I don't know what "Show Details"  Is .  I don't see "Scale to Fit" nor "Actual Size"  In the drop down box below "Scale " I see: "Fit to Printable" and "Shrink to Printable."

Very confusing. 

[firstdefence]

What is the mats outer dimensions?

For images I want to frame and use a Mat, in Affinity Photo I create the mat as an overlay within the bounds of the paper size to be printed onto and print to actual size, this gives me a digital view of how the image will look, at the point of printing I just turn the Mat overlay off and print to the paper size, I also create a rectangle with a small stroke but no fill to represent the frame recess, I leave that turned on so that it prints a fine line that I can use to cut the paper to fit the frame recess. 

Nesting the image to the mat inner dimension gives you a visual representation of how the image will look with the mat overlaid. There can be a bit of fine tuning if no white space will be added i.e. making the mat inner dimension slightly larger to avoid white lines or just un-nesting the image so it prints a "bleed" see below.

[walt.farrell]

What OS platform (Mac, Windows) are you on, @Edwa?

I think there is a reported bug for one of them where the Print dialog sometimes shows the red highlighting even when the image will fit. Perhaps just try printing and see if it works. (Or enable print preview if your printer driver supports that.)