Mitered Border Corners

Written by Karen Schreiter


Posted on June 20 2018

For a lot of beginning quilters, making mitered corners is a bit well, terrifying. It looks complicated. Today we are going to take the fear away and you will actually be ready to do this technique on any of your quilts or quilt blocks.

To show you the difference between mitered corners and traditional corners, we have made two samples. You will notice the one on the left is the traditional way to add your borders. Your border is as long as the quilt is long and then ends and the top border is then sewn across.

If you are using stripes, this can be a bit abrupt. By mitering your corners, you can make the fabric appear almost seamless as it travels around the corner. This is pictured on the right.

Corner comparison of mitered vs. traditional quilt borders

The first step is to square up your quilt top. Take a square ruler and place in each of the corners. If anything needs to be trimmed, do it now.

Squaring corners

For this tutorial, we will be working with an 18 ½ x 20 ½ inch square. Our border strips will be 3  inches wide. In order to determine the length of our strip, we will need to use this formula:

We have already cut our border length at 30 ½ inches. We now need to cut our border width at 3 inches. To keep the continuous flow, you will want to start and stop your cutting at the same spot for each strip. You might need to trim some excess fabric to keep your stripe in the same place. For this step, we are using a red and pink stripe fabric from Tula Pink's All Stars Collection. We will start each one of the strips on a pink stripe. We have cut away the extra red stripe.

Trimming extra fabric

Now, go ahead and cut your first strip- for this tutorial, we cut the strips at 3 inches wide and are using the Creative Grids 3  x 12 inch Turn Around Ruler.

Cutting 3 inch strip

Once the first strip is cut, put a marker (we used a Clover Binding Clip) on the side of your first cut. This will help you remember what side is to be sewn to your quilt top. This is also important because it will keep your stripes flowing around your quilt and they should match up on the diagonal when you are all done. Notice that the marker is on the pink stripe.

Marking sewing side

Now cut the second border strip for the 20 ½ inch side. Remember to cut on the same stripe and put your marker on the same stripe.

Mark sewing side of both strips

Our next step is to mark the center of each of the 20 ½ inch sides of your quilt top. Fold the edges together and put a pin in the fold. Do this on both sides of your quilt top.

Marking quilt center

Then, mark the center of each of your 20 ½ inch border strips on the side you will be sewing to your quilt top. Fold edges together and put a pin in the fold on the edge that is to be sewn to your quilt top.

Marking center on border

Now, mark the border strip to measure 20 ½ inches. Start from the center pin and go out 10 ¼ inches on both sides. Then do it on the second strip as well.

Measuring off of center

Now, we are going to attach our borders to our quilt top. First, match up centers and pin.

Matching centers

Then, match up each edge that is marked and line up on the end and pin. You can now fill in with extra pins if you would like. Then go ahead and do the opposite side.

Pinning to edges

Before we can sew, we need to measure in 1/4 inch from each edge. With a Frixion pen and a ruler, measure in and make a mark. You should have 4 marks at this point, one on each corner of your quilt top.

Quarter inch

Quarter inch mark

You will sew from each of your 4 marked lines - line to line- using a 2.0 stitch length and a 1/4 inch seam. Put your needle down exactly at the first mark, take a couple of stitches forward and backward, doing a tack stitch.

Put needle down at mark

Sew directly to your mark and make sure to do a tack stitch at the end as well. If you go beyond your mark, you will want to unpick those stitches.

Stop sewing at mark

Sew the other side the same way. Press seams towards your border.

Press to border

Now, let's move to the shorter sides of your quilt. Let's review our formula, but note that the numbers change because it's the shorter side:

Formula for shorter sides

We have gone ahead and cut our borders for our 18 ½ inch sides of our quilt. They measured 3 inches wide by 28 ½ long. Find the center by folding in half and placing a pin in the fold.

Marking center on border

Again, you will mark the center of your quilt top. Gently fold the already sewn border out of the way and match each corner to find the center.

Center matched edges

Then mark the centers of your border strips and measure out from the center pin 9 ¼ inches and put a pin in there.

Marking second border from the center

Line up the centers and begin to pin. When you get to the corners, move the other border gently out of the way. Simply fold it back so you can see your corner, Line up the edge and pin.

Matching border edges

Now, flip your quilt top over so you can see your previous stitching. Put your needle down exactly where your stitching ended on the other borders. If you do this, you will not have any puckers or open spots. Be sure to do a tack down stitch at the beginning and the end.

Start at previous stitching

Complete your seam by ending at the other corner where the former stitching started. If you stitch too far over, you will need to unpick these stitches.

Stop stitching at previous stitching

Now, you can see you have your four borders attached. You also have four tails. It is supposed to look like that. Press all seams toward the borders and make sure you don't have any holes or puckers.

Uneven borders

Fold your quilt on the diagonal. Don't be worried about the quilt, BUT pay very close attention to your borders.

Fold on diagonal

Line up your border strips along the top and bottom, right sides together.

Lining border edges

Put in a lot of pins to keep the edges of the border together.

Lots of pins

On the back side,  you have a seam that is pressed towards the border. You need to flip that seam up and put a pin in it to hold it up. By doing this you will not get a pucker when you start stitching.

Fold up seam allowance

With everything lined up, take a ruler that has a 45 degree angle marking on it. You will push the border seam up and line your 45 degree marking on the stitching line. 

Use 45 degree line on ruler

Put 45 degree line on stitching

Using a Frixion pen, draw a line right where your previous stitch ended to the edge of the border fabric. You now have your perfect miter.

Drawing sewing line

Put your needle down exactly where your previous stitching left off. Sew on the drawn line.  NOTE: If you start stitching at the edge of the border, you will end up with puckers. Be sure to do a tack stitch at the beginning and at the end of your stitching.

Sew border seam

You have sewn your first border. Open it up and make sure it doesn't have any puckers. If you have any problems, fix it before you cut the excess fabric away.

Double check before you trim

Make sure that everything is out of the way and lying flat. With a ruler, cut the excess fabric away leaving a 1/4 inch seam allowance.

Trim excess

Now we are going to press.

We will press from the back and press the miter seam open. Gently open the seam with your fingers, then using the tip of a hot iron press flat along the seam.

Finger press seam open

Pressing seam open

Then you want to take the flap where the quilt top and borders meet and press it toward the borders.

Pressing quilt top point down

Turn quilt back over and give a really good pressing from the front.

Congratulations! You have made your first mitered corner borders.

Finished miter corners

Supplies used in this tutorial:

Olfa Splash Rotary Cutter

Olfa Rotary Blades

Flower head pins

Havel Seam Ripper (good to always have on hand)

Clover Wonder Clips

Frixion Pen  

Creative Grids 3 x 12 inch Turn Around Ruler

All Stars by Tula Pink