Print JPEG Letter Size

[Borgward1]

jpeg is 349 X 459. How do I print it so it fills up 8-1/2" X 11 sheet?

I did this once before, but the image just prints a lot smaller.

Using HP Office-Jet Pro 6970. Can't remember what printer I used before.

[rich2005]

The usual way for printing is adjust the printing resolution using Image -> Print Size  US letter is 8.5" x 11" but your printer (usually) requires borders, so change units to inches, and in this case Height rules so set the height to maybe 10.5, whatever you think suitable.  Starting with a small image the print resolution is now equally small and the print is going to be poor quality.  All depends what you are printing, packing case label or the Mona Lisa. Screenshot: https://i.imgur.com/Xyg1eHr.jpg

The other way is open a blank USletter canvas, there is a preset  File -> New -> Template Open the small jpeg as a layer File -> Open as Layers
Use the scale tool and drag the jpeg layer to size. Use the corner 'handles' to keep aspect ratio. Screenshot: https://i.imgur.com/J5a0qLh.jpg

These shown in kubuntu 18.04 / Gimp 2.10.22 but Gimp 2.8 is similar. Can you install the Gimp-Gutenprint plugin? (all depends if the printer is supported) That can scale a image for printing.

Edit: Pulled the 2.8 (portable) out and are you saying that this does not work with regular linux CUPS print ?  Set the paper size / Set one of the (W / H ) image size