7" total, so 3 1/2" each on the top and bottom. Gosh, that's less than I thought now that I look closely. Maybe it won't even be too obvious.
The pattern is called "It's an illusion" and it was in a free issue of the Missouri Quilt Co magazine just recently. (Someone on this board clued me in to this free issue.) Each block is 7 x 12. I haven't even begun to cut yet. Just planning. I could also play around with arranging the blocks with the long side horizontally, not vertically.
Here's a link
http://land.missouriquiltco.com/illusionblock/
I've just noticed the pattern doesn't even call for a border. Maybe I'll do that instead?