I could not bear to cut into this panel. So I went into my closet bins looking for fabrics that would match and not detract from the print.
I found a Fall orange-ish batik fabric that has grays in it that I used for the first 1" border. It matches some of the trees as light shines on them. Then I found a couple of greens and made a 2.5" second border. The other green was a perfect match with white fabric that has pine needles and pine cones with a little snow sparkle to it. Right now, it measures 42" wide by 60" long. There is a bit of green pine left and some of that orange. I have a lot of white fabric and could use that for the back. My thought is that it needs at least 10" more on both sides, and about 8" more on top and bottom, which would come close to making it 62"x78". Of course, I am just guessing at this point. The remaining borders will go on as they do. I plan to get to the fabric store and would like to purchase a brown batik, but will take what I have made to match it. Right now it is pretty green and a darker last border will frame it nicely.
I am so glad I decided against cutting into it.