You need to do a few things...
1) Make sure your image is 12x12 (I'm assuming you want to print a layout here). It seems obvious, but sometimes if it's a page that you've scanned and stiched, it's not a true 12x12.
2) Go to File | Print and chose the 1280. Click on "Properties". Change the media type to Matte Paper Heavyweight if you're using Epson's scrapbook paper. If you're using something else, that setting should still work, unless the finish is glossy.
3) Still in Properties, click on the "Paper" tab at the top. In "Paper Size", scroll down to the very bottom where it says "User Defined" to set up the scrapbook size. Name it whatever you want (mine is called "Scrapbook") and enter the size. If you have the new paper that is true 12x12, put in 1200 x 1200 (it's in .01 inches). If you have the old paper in the white and blue box, it's 11.6x11.6, so you'd put in 1160 x 1160. Hopefully you have the new paper (it's in red packaging)! Save that size so it will always be there for you (it will be at the bottom, under "User Defined". Make sure it is selected.
4) Under "Printable Area", chose Maximum and Centered (just click ok for that warning that pops up). Then you're ready to print!
Just so you know - the 1280 does NOT do a borderless 12x12 print. It will leave a small (1/8 inch) white border around the edge. The only printer of ours that does borderless 12x12 is the brand-spankin new 1800 (basically, the wide-format version of the R800).
As far as your inks go - sometimes it can take up to 10 times to clean the print heads fully. That's pretty rare - usually 1-3 times does the trick, but it's worth a try before you replace all your inks. I've had to do it on my 1280 a few times when I've had it shipped.
Hope that helps!
