How to Add Borders with Mitered Corners to a Quilt
Adding a border with mitered corners to a finished quilt top lends a neat, finished appearance. A mitered corner is made by sewing border strips on to all four sides of the quilt and then folding the corner fabric into a 45-degree angle so the corner has a diagonal line extending from the corner of the quilt to the corner of the border. Sewing a border with a mitered corner onto a quilt is not much more difficult than making a corner with straight lines.
Things You'll Need
- Rotary cutter
- Cutting mat
- Sewing machine
Measure the length and width of your finished quilt top.
Add 8 1/2 inches to the both the length and width measurements. This adds 2 inches on either side to account for the width of the borders plus 1/2 inch for seam allowances.
Cut two 2 1/2-inch-wide strips of fabric to match your length measurement and two 2 1/2-inch-wide strips of fabric to match your width measurement.
Find the center of each of your quilt top sides by folding the quilt in half and placing a pin at the fold. Do this for all four sides. Find the center of each border strip by folding it in half and placing a pin at the fold. Do this for all four border strips. Place each border strip on top of the quilt top with right sides together, lining up the center pins on the quilt and border strip, and pin the border strips to the quilt top at the centers. Place additional pins 1/4 inch in from each edge and then another pin halfway between each edge and center strip.
Sew the border strips to the quilt top, starting 1/4 inch from one corner and ending 1/4 inch from the opposite corner. Backstitch at the ends of the seams to secure them. Leave a 1/4-inch seam allowance. Do this on all four sides.
Begin working the mitered corners with the top left corner. Allow the excess border fabric from the top border to overlap the excess border fabric from the side border.
Fold the end of the top border under itself to form a 45-degree fold and crease the fabric. The right sides of the top and side border should now be together and both should be pointing up. Pin the border strips together in this position.
Fold the quilt top in half diagonally so the fold in the quilt lines up with the 45-degree angle created by the border strips. The right sides of the border strips should be together and extending up.
Pin the fabric together along the 45-degree angle line in the border fabric and sew the fabric together along the crease. Trim the excess fabric away about 1/4 inch from the seam.
Turn your quilt so you have an unfinished corner on the top left, and repeat the process until all four corners are mitered.
- Use a bias square ruler to check that your corners line up and are at 45-degree angles before sewing them.
- Mark your crease with a fabric pencil if you're having trouble visualizing the crease when sewing.