What is a mitered corner? Why do you need one?
A mitered corner is a neat way of finishing the corner of a fabric edge in such a way that there is no bulk in the corners when the fabric is turned under to finish the edges.
The easiest way to finish a corner is to turn under the edges as is but the corners prove bulky with the four layers of fabric. It sure looks ugly. But with the mitered corner technique you have a border or a hem which looks neat on the front as well as the back.There is an attractive 45-degree seam along the corner.
You can easily hand sew a mitered corner or stitch it with your sewing machine. But I would prefer hand sewing for the corner stitches, for more precision. Another good practice is to prewash the fabric before sewing. This will prevent your mitered corner skewing after a wash.
Method one – self-turned mitered corner
In this method the fabric edges are turned to the back of the fabric ( or the front for a border like effect). This is the most preferred method of finishing the edges of napkins, blankets, bedspreads etc. The hem looks wonderful with no bulk on the corners.
How to sew this mitered corner
Cut the fabric edges really straight. In case of blankets napkins etc you have to ensure that all the four sides are cut really straight. In case of cotton fabrics you can rip and you will get a very straight edge. You can use the transparent square scale to get straight edge, as well.
Turn the edges 1/2 inch to the back of the fabric. Press in place.
Turn the fabric edges again the width of the first turn ( 1/2 inch, it was). Now you have made two folds for each edges. Finger press the edge fold.Mark the inside edge of this second fold with a chalk.
Open up one fold ( the second one).
( Donot mark as drastically as I have done with red ink. You just need an indention to know the meeting point ( the black dot ) in the picture.)
Now bring the corner to meet the black you have made earlier
Crease nicely. Mark with a chalk on that line – you need to see the line; you will be stitching through it later.
Fold the fabric so that the corner is pointed and the line you had made earlier is on either side. Stitch through the line you have marked ( red line in the picture below). Start and end the stitch with back stitching.
Cut the extra seam allowance; press the seam open.
Now turn the edge inside out so that it looks like the picture below. You can top stitch this mitered fold in place along the edge.
Method 2 – Mitered corner with a fold
You can achieve a similar mitered look without cutting anything.You should first finish the edges of the fabric with a zig zag finish or rolled hem finish. Mark a line 1/2 inch to the inside from the edges. Then turn the corner to the inside along the corner mark.Now fold the other folded edges to the inside . You will get a mitered corner. Stitch the folded fabric in place.
Method 3 – Mitered corner with a Border
This method is used when you need to make a border for the fabric with a different coloured / patterned fabric than the main fabric, like for a shawl. With this method you will still need to finish the raw fabric edges after the border with the mitered corners are stitched.
For this method you need 2 strips of fabric ( for one corner) 1 inch wide and length 2 inch more than the fabric edge of each side.
Keep the fabric strip mid point aligned with the fabric edge midpoint
Stitch the edges together. One important thing here is that you have to leave 1/4 inch unstitched on either side of the fabric edge.
Now turn one short edge down as in the picture below
Keep the other fabric strip on the adjascent fabric edge. Stitch the same way, along the edge, leaving 1/4 inch on either sides unstitched.You will find that you have a snug corner there already. Now on to get the mitered corner for your border strips.
Fold the fabric diagonally. Keep the fold along a scale; you will see that the scale is overlapping the fabric strips. Mark where the scale touches the fabric strip ( red mark in the picture below)
Stitch along that mark. Remember not to stitch the main fabric ; You will find that you are starting to stitch from the last stitch on the fabric strip, along the line you have marked.
Cut off the excess seam allowance. You will have a beautiful border with a mitered corner as in the below picture.