Borders are almost pieced in quilts larger than 40 inches. Most patterns call for borders cut on the crosswise grain which means they have to be pieces. I personally like to cut lengthwise borders on the lengthwise grain and crosswise borders on the crosswise grain. This means that I cut the borders first-of course, they are a bit longer than estimated-just to be sure. I use a diagonal seam and match the pattern whenever possible because I like it to not be obvious. By the time I quilt it, the seam is absolutely gone and I haven't spent a fortune for unneeded yardage.