ET-2550 How to work around the borders to get the exact image size?

Hey, sorry if this is the wrong place to post!
I'm printing proxy cards so it's important to print the image the exact size that it is. I'm printing on 6x4 photo paper. First, the image was enlarged, almost filling the whole paper, the "size to fit" on or off made no helpful difference. So I made the image file itself 6x4 (filling it with a white background) so the card image would be exact. And that would have worked, but the borders shrink the entire document, making the cards about 0.4cm off each way. Apparently the ET-2550 can't print borderless, so I'm stumped. I tried printing with my iPad where you can pinch to zoom the image in and out, but this means even if I try to somehow pinch zoom it to get it perfect, it won't be exact, and definitely not every time too. Is there a way I can get around this? I don't want to edit the image file size itself because it looses quality. Thank you in advance for any help.

 

Sorry for the double posting, here's photo examples of what's going on and how much the borders are shrinking it.