This is Affinity Studio - completely free... let me say that again... 100% free, desktop class PhotoShop like software. It will do what 99.9% of what anyone doing POD needs. It is made by Canva but it is not Canva online with all its restrictions. https://www.affinity.studio/download Yes it as a bit of a learning curve but there is a huge community behind it. It used to be split into 3 apps called Photo, Designer and Layout but Canva acquired Affinity and merged them into one full editing application for Mac / PC and soon iPad. Check out YouTube!
Anyway here is hopefully something to help people who have to change A size to fit a non-A size print. As you can see depending on the Ratio it depends on what you need to do = 🔴 Red Areas in image 1
You also need to consider elements like text / logos - this requires some thought and may not even work in certain ratios! As you can see 1x1 is a problem hence the --ar 70:99 you tend to work to.
2x3 and 11x17 are a little easier since they are narrower then A sizes you can centre justify your entire image and probably that will do (sometimes it may not).
But lets look at 11x14 (bottom left) and it's mini version which is actually 11x14" on my canvas I was just doing this do show it does not matter if you shrink down an image to a smaller size it's the same issue!
🚨 Remember: lock the aspect when you change size so you do not stretch the image!
You can pretty much just scale A size up to fit the 11x14 ratio, but you clip a bit off the bottom.. This is fine on the image with no text, but when there are elements that are important it is an issue.
As in Image 3 you need to move it up not just crop it, then the text is not cut off the page.