Generic Black rounded edge card frames for HQ scans?

Hello I am totally new to this forum and the whole proxy process.
I noticed that the sample HQ scans shown on this website all have a very thin black border and the corners are not rounded like the regular MTG cards.
How do I go about getting a thicker rounded edge card frame on all the HQ scans from this website?
Thanks!
I noticed that the sample HQ scans shown on this website all have a very thin black border and the corners are not rounded like the regular MTG cards.
How do I go about getting a thicker rounded edge card frame on all the HQ scans from this website?
Thanks!