Linked PSD incorrect scale

The issue seems to be well known, due to how photoshop handles files of varying initial size, because it sets the dpi values at the file creation.

So if you work with ui and have a 2k file, you produce some group of elements, dupe them into a new file, and then trim transparent pixels, the actual image size will be small, say 200*300 pixels. However the DPI will still be the same as in 2k file.

Now if you make a new file with different resolution and as a consequence with a different DPI, upon linking of that element psd it will have an incorrect scale due to dpi difference.

This is a pretty dumb issue with how photoshop works, as DPI is rather pointless in non typographic workflow, it does affect things like shape scales, so i assume dpi serves as a backbone for a lot of scaling operations in PS.

So to fix this, you will have to change the dpi of the file you are linking, this will introduce scaling and potential artifacts with shapes/lines/layer effects, but nothing you can't fix.

So in general the advice is - keep track of your dpi, make sure all files, even those you will later crop have originally the same 4k or 2k or whatever is your template resolution so that the dpi stays consistent across all your assets.