I’m just gonna say it: I love mitered borders on a quilt! Unless there’s a strong design reason for a straight-set border, mitered borders are my first choice for border treatments despite the small amount of extra work involved.

Depending on how many borders the quilt has it’s actually no extra work at all, since you can apply multiple borders all at once instead of one at a time like you’d do for straight-set borders. Not only can you apply multiple mitered borders all at once, it’s really the better and more accurate way to do it, and you’ll get the most lovely matching corners if you do! Here’s the complete how to:

Step 1: If the pattern calls for mitered borders, cut your borders according to the pattern directions. If the pattern calls for straight borders and you’d like to add mitered ones instead, you’re in for a little math, so here’s the formula I use for a triple border with A being the first border next to the quilt center:

Quilt center size + 2(Border A finished width) + 6″ = Border A length

Quilt center size + 2(border A finished width) + 2(border B finished width) + 6″ = Border B length

Quilt center size + 2(border A finished width) + 2(border B finished width) + 2(border C finished width) + 6″ = Border C length

And of course if you’re adding even more borders–you overachiever, you!–just keep on adding to that formula with the same pattern! Let’s break that down even further and add in some plain English:

Quilt center size: for the top and bottom borders for example, measure the top middle and bottom of the quilt, add these together and divide by three to get the average measurement (this will keep your quilt nice and square or rectangular which is especially helpful if your quilt has a lot of pieces and might be a little off from the top to the bottom!).

2(Border A finished width): What’s the finished width of Border A? Multiply this number times two.

Add 6″ to this total. That extra 6″ includes seam allowances and insurance! You don’t want to run short on that diagonal seam line for the miter.

Use this formula to calculate the cut measurements for each border. You’ll need to calculate the top/bottom borders and the side borders separately unless your quilt is square! As an example, let’s say my quilt center is 15″ x 18″, and my borders are 1″, 1½” and 3″. My math for the top and bottom borders would look like this:

15 + 2(1) + 6 = 23″ (this is the cut length for Border A)

15 + 2(1) + 2(1.5) + 6 = 26″ (this is the cut length for Border B)

15 + 2(1) + 2(1.5) + 2(3) + 6 = 32″ (this is the cut length for Border C)

Do the same for the side borders to calculate the cut lengths. Whew! Okay, done with that math stuff.

2. Lay the quilt top aside for now, and sew the borders together. Yep, strip piece each border set together in the order that they’ll be attached to the quilt, matching the centers of each strip. The easiest thing to do is fold each strip in half end-to-end and finger press a line in the middle, then match the middles and pin. The ends of the strips won’t match up, and in fact you don’t want them to. Remember that diagonal seam you’ll be making on each end! The ends of your border units should look a bit like this after sewing them together, and you should have four units:

3. Pressing–this is a biggie! On the top and bottom units, press the seam allowances toward the outside border. Press carefully with a dry iron, so that you don’t stretch the unit out of shape! On the side units, press the seam allowances toward the inside border. This pressing technique is the key to easily matching the corners of the mitered borders later, and thus very important!

4. Okay, let’s get down to the real business of attaching the borders to the quilt, working with the top border first. Fold the top edge of the quilt in half and finger press a crease right in the middle at the edge. Do the same for the top border unit, finger pressing a crease in the edge of the inside border. If you can’t see the finger crease well enough, you can mark with pins or a (removable) marker of some sort.

Remember that “Quilt center size” measurement? Divide that number in half. Use a ruler to measure that distance from either side of center of the top border unit and mark as shown below. I used pins to mark these positions.

5. Pin the top border unit to the top edge of the quilt, matching centers, and matching the outside pins to the side edges of the quilt top. Turn the whole thing over so that you’re stitching with the quilt top on the top–it will make this so much easier to see what you’re doing! Begin stitching ½” from the quilt edge and back stitch to ¼” from the quilt edge, then stitch forward as shown below. You can certainly mark this ¼” spot with a pencil if your machine doesn’t have a ¼” mark on the sewing foot to help you out. However you do it, marking with a pencil or using the foot on the machine, not stitching beyond that ¼” spot is very important! Stop stitching ¼” from the other edge of the quilt, and back stitch.

Repeat for the bottom border. Press top and bottom border seam allowances toward the border units, being very careful at the outer edges. The quilt edges have a tendency to stretch if not treated gently where indicated by the circle in the photo below.

6. Take a quick moment to fold the floppy ends of the top and bottom borders back on themselves and pin to keep them out of your way. Now on to the side borders!

Again, fold the right outside edge of the quilt in half and finger press a crease right in the middle at the edge. Do the same for the right side border unit, finger pressing a crease in the edge of the inside border. Remember that “Quilt center size” measurement? Divide that number in half, and this time, subtract ¼” for the seam allowance. Use a ruler to measure that distance from either side of center of the right side border unit and mark each side with a pin.

Lay the right side border unit on the right edge of the quilt, matching centers and matching the side pins to the seams between the quilt center and the top and bottom borders, as shown below.

Once you have everything lined up, scoot the border up so the edge is even with the quilt edge, and pin. Turn the whole thing over so you are stitching with the quilt center on top, and as before, begin stitching ½” from the edge and back stitch to ¼” from the edge, then stitch forward. At the end of the seam, stop stitching ¼” from the edge of the quilt center, and back stitch. The corner should look like this when stitched:

Repeat Step 6 for the left side of the quilt.

7. Right now, you’ll have a quilt top with a bunch of flapping border corners. Don’t panic! We’re going to do some magic with those corners. 🙂 Let’s take it one corner at a time.

Lay the quilt on the table, and fold the right side of the quilt upward diagonally until the raw edges of the right side border and top border match. You should be able to feel that the seams between the borders are “butting” together, since the seam allowances are pressed in opposite directions! Smooth the whole quilt so that it’s nice a flat, and the raw border edges and seams between the borders are matching up.

Lay a quilting ruler on the border, lining up the 45 degree line on the raw edge of the border, and keeping the edge of the ruler even with the diagonal fold in the quilt as shown:

Use a pencil or a marker to draw a line at the right edge of the ruler. Here’s how it should look at the inside corner. The drawn line should connect with the stitching line:

Pin securely along the marked line, paying special attention to the seams between the borders to insure they match well. Stitch on the marked line, starting from the outside corner and stopping where the marked line meets the stitching, and back stitching to secure. As you’re stitching toward the inside corner of the miter, pay close attention so that the seam allowance from the border underneath is not caught in the stitching. Where the seam allowances all come together in a three way seam can sometimes be tricky! See below:

Unfold the quilt to check that the border corners match well, and use a square ruler to check that the outside corner is really square! If you’re happy with how it looks, press the seam allowance lightly toward the top border. I strongly recommend waiting to trim away the excess border pieces until all four of the corner miters have been stitched. Adjustments are much easier to make before trimming!

8. Repeat for the remaining three corners. I usually press the miter seam allowances toward the top and bottom borders. After stitching all the miters and pressing lightly, lay the quilt flat on the table or floor to check that the borders are flat and straight, and that the corner miters match well.

Troubleshooting! If the corner miters lay flat, but there are ruffly spots in the borders, OR if the corner miters have a lump in them and won’t lay flat, check the angle of the miter sewing line. If the 45 degree line of the ruler isn’t lined up on the edge of the border correctly, the miter angle will be off! Also, check that your miter sewing line really meets the sewing lines between the borders and the quilt center properly–that’s another trouble spot.

When you’re satisfied, trim away the excess border pieces with a rotary cutter and ruler, leaving a ¼” seam allowance, and press well. Ta-daa!!! Perfect multiple mitered borders made easy!

Wow!! That wasn’t so hard, was it? Once you’ve done a couple of mitered borders, it’ll just be old hat stuff! 😀 What about you and mitered borders? Love ’em or hate ’em? Done it a lot, or afraid to try? Give it a go, I know you can do it!