- Measure and jot down your quilt's length and width.
- Decide how many strips will make up your borders and choose your fabrics. My quilt has three strips per border: two are my hand-dyed fabric, and the other is the black fabric.
- Borders are applied, one at a time, on each of the 4 sides of the quilt. The length of each border = (the length or width of the quilt top) + (3 x the width of your full border) + 10" more. Your borders will be quite long, but you don't want to make them too short. **If you skimp on the length, you will not have enough fabric to sew your miters.
- If you are using more than one strip in your border, sew the strips together and press; then cut to length. (You'll need 4 of these borders, of course, if your quilt has 4 sides.)
- Now fold your border in half to find its center, and finger press to mark it. Mark the center on that side of your quilt.
- Place your quilt on top of your border, right sides together, matching the center of the border to the center of your quilt edge, and pin.
- Begin sewing 1/4" in from the edge of the quilt and back tack there, then sew until you are 1/4" from the other edge of the quilt; back tack again.
- Attach the remaining three borders in the same way.
- When all 4 borders are attached, and their ends are free, fold your quilt in half, diagonally (see photo).
- Now, line up your two border strips perfectly and pin to keep them in line, as in the photo. Click on the photo for a larger view.
- Make sure that your quilt is folded on the diagonal from end to end, then lay a ruler down to continue the diagonal line to the border you're about to sew. Mark that line with a soap sliver or chalk, and pin again for sewing.
- Sew this line with a basting stitch first, if desired (I baste first). Sew on that line from the outside edge, right up to, but not passing, the place where your borders are sewn to the quilt.
- Lay it open and see how it turned out. If it doesn't look good, tear out the seam, straighten your lines, pin and try again.
- When the corner is mitered the way you like it, trim your seam to about 5/8" and press it out, up to where all the corner seams meet. Now press the corner of your quilt flat over it. You'll understand when you see it on your quilt. The corner of my 9-patch pressed flat right over my pressed-open seam. It's all in the math.
- Now do it three more times.
The more you do mitered borders, the easier it will get. The first time I sewed a mitered border it turned out fine. There's always one that isn't perfect that I have to pull out and re-do, but it's not the end of the world, and it looks great when finished. I nearly always baste my seam first to check them.