Adding a simple white border without quality loss

Hello, I can't seem to find an easy workflow for this anywhere, which seems baffling in this day and age. All I want to do is create a simple "x amount" or "x percent" border without any change to the actual image quality.

I primarily use Lightroom on iPad for editing as well as some Lightroom on Windows desktop. There is a feature called "scale" under Geometry that allows one to shrink the image down to 50% size using a slider, creating a surrounding white border. However, unless the image is square, the border disproportionately thickens on the shorter ends of the photo. I would like just an evenly spaced border all around.

The suggestions on the internet involve using the Print module in Lightroom desktop, which seems overly laborious, especially for cropped photos of unusual dimensions. I also don't use the desktop right now nearly as much as my iPad for editing, for various reasons.

Does anybody know of an app or a program (or feature in Lightroom) that can do this easily and definitely does not affect image quality otherwise? Thanks

Photoshop can do it easily by increasing the canvas size uniformly around the image. Literally adds however much white pixels to each edge while changing nothing.

Programs like Paint Shop Pro have the ability to add pixels to an image. Ohe thing is to add a simple border of N pixels along the 4 edges of the image.

If the editor has no simple tool for that (which I can't imagine actually) a universal way of adding borders is to make a new image with the size including borders, optionally change the color, and paste a copy of the photo onto the new image. The width of the border is the difference in size between the new image and the photo divided by two, which is also the position where to paste the photo (pixels X, pixels Y). I sometimes do this when making postcards and the photo is square, which needs large asymmetrical borders.

PFGS said:

Photoshop can do it easily by increasing the canvas size uniformly around the image. Literally adds however much white pixels to each edge while changing nothing.

Click to expand...

This. Go to Image > Canvas Size. You can do a variety of things here. Check “Relative” to add or subtract a given amount, or leave it unchecked to key in new dimensions. You can also make a Canvas Size adjustment an Action (Window > Actions) that can then be performed with a keystroke, or built into an automated workflow.

edited for clarity

It looks like you have to use the print module if you are going to stay in Lightroom - there doesn't appear to be a canvas size option.
All the applications I'm familiar with for adjusting the canvas size are Windows specific.