To print borderless photos, all I SEEM to have to do for my new NX400 is select it in the printer driver options. Then again, all I’ve used to print is Windows’ built-in photo printing utility, an old version of PictureIt!, and GIMP. Each of those applications worked fine without changing any settings within the program and only tweaking the borderless option in the Epson control panel.
The control panel shown in the Epson Stylus Photo R320 Printer Basics document/guide looks somewhat different from my screenshot. Does the borderless option appear/work differently from either my screenshot and/or the screenshot shown in the document/guide on page 39?
Slightly less likely of an oversight, I also remember using my HP PhotoSmart 7850 to print borderless photos. I found that some paper was advertised as 4x6, but had a little extra length to give it a “tab” [and this wasn’t totally apparent to me from just reading the package]. In order to print the full length [and not have the extra “tab”], I had to choose a different option from the normal 4x6, and it printed the full length of the paper. It only affected the 1 edge of my paper, though, and didn’t leave a border around the whole thing.