I also would border it....just to stabilize all those little squares. Mine never seem to be perfect when I end up and when you machine quilt it, I think you'll want something to square up at the end, otherwise, you might be cutting into the squares. I did a Scrap Therapy class a few years ago and have a box and a half of 2" squares. At the time, I was wondering what in the world I would do with all those really small squares but its funny, those seem to be the ones I reach for most often. I've even searched out patterns such as yours to use them in. Yes they are small, but I use them for my "mindless" sewing....when I just have an itch to sit down and sew but don't want to have to think about it.