The first and only time I used a panel, they were so crooked that I added the border larger than I needed and then squared the whole thing - Hope this makes sense.
Life is like a quilt...bits & pieces, joy & sorrow, stitched with love
Regarding panels: I do a heavy spritz and let them dry without stretching. I then press them (not so much iron...) then I measure and assess the panel. Did it straighten on it's own? Sometimes it the way that it was on the bolt or hanging in the store. If it is off a little, a border sometimes is all it needs, othertimes I try to find a place that is straight and work from there. I have had a few that I just cut up and made a different sort of quilt.
Caryl in Buda, TX
I've never been sure how to square up a quilt. I put it together then fold it over and trim off the places that aren't even. I had a quilting friend that always did that for me and she passed away this past fall. So I could use instruction on squaring up also.