What a great question! I have yet to make a quilt using a panel, but it is on my to-do list for 2018. Some on the Board have advised adding a border and then squaring that, which kind of makes sense to me. However, I am wondering, does the quality of the fabric makes a difference? The reason I asked is that I've just finished a throw quilt top made up of five 10" X 44" strips (in part). The two outside strips and the center strip are from one print fabric and the two strips next to the outside strips are from another fabric. I cut these two strips from a vertically printed fabric, omitting part of the design -rather like creating a vertical panel. I was very concerned that these two strips would not be even (square, I guess). I need not have worried. The fabric was Timeless Treasures (which I had never used before -and, oh, it was lovely in design and quality). Anyway, just a thought... Does this even seem like a legitimate consideration when buying panels? If so, any recommendations as to brands?