ok, thanks. I took off the borders & it's more wrinkly than ever so I assume it must be an issue with the fusible web. I've been having lots of issues with it anyways since it comes in 18" width & the fabric is nearly twice that, and on top of that there the butterfly fabric has thread pulls & holes in it (which is why I backed it in the first place). There were some minor issues with it when I started sewing the borders, but I thought they were manageable. Not only did they get worse after I sewed on the borders, but they continued to worsen as the night went on. Now having removed the borders, the wrinkles are even worse.
Guess I'm off to wet it down & see what happens with that. Hopefully I will not have to go & buy yet another product to finish this nightmare quilt, but I will keep the SF-101 in mind if I do. Thank you all for the ideas!
PS -- I found some information on a few different sites about pre-shrinking the interfacing by setting it gently on top of the fabric & then steaming it until it seizes up a bit before pressing it onto the fabric. I never realized that was important, but I guess I've always done that with my applique work simply because it allowed me to heat it up a bit & place it in the perfect spot before pressing it down. I can't imagine how I'd do that with such a large section, but maybe instead of putting the interfacing on in strips, I need to cut it into squares & attach it in small 12"x12" sections. idk. so frustrating!!!