Miter Corners - Paper Sewing

When we sew a hem at a corner, we might have trouble with too many layers overlapping, especially with a very thick fabric. We might experience symptoms like needles breaking, fabric jamming, stitches varying, and corners protruding.

It's remarkable how quickly we can stack up six layers of fabric when we start with only one. We fold our frayed edge, and then we fold it again to cover itself. That puts two layers on top of the original layer, making three. At the corner we are folding one hem over another hem. That puts three layers on top of three layers, so we have six.

Not only is this much thicker than our one orignal layer, but it is also unbalanced. As we sew toward our corner, we are piercing three layers. Suddenly our presser foot crashes into a wall of three new layers, and that wall wants to fall away from the presser foot. If our presser foot manages to climb that wall, the fabric will probably be pushed out of alignment. Then our needle, piercing six misaligned layers, may be pushed so far that it strikes the needle plate and breaks.

One way to solve this problem is to stop overlapping one hem onto the other hem. Instead, we can bring them together end-to-end, at a 45 degree angle. This is called a miter or mitre.

Download this PDF to get started.

We can practice this with a piece of paper. We fold each edge twice, creasing the paper, to make our usual hems. Now if we unfold the paper we can see where the finished corner will be, where the innermost creased lines meet. We fold across that corner at a 45 degree angle, so that the tip of the paper is pointing toward the middle of the page. This dog-ear fold crosses both hems.

Now, we are going to cut away most of this corner, but we want to stay away from where our finished corner will be. If we cut exactly across that finished corner, then we will have ragged threads protruding from our garment. We want to protect that corner. Move the scissors out. Look at the width of one of the folds and move the scissors about that far. Now cut off the corner.

Fold down the remaining tab. Keeping that tab pressed down, fold each of the seams back into place. Now see that the two seams meet end-to-end, along a clean angle. The maximum number of layers is now four, where each of the folds overlaps the little tab.

The arrangement is well balanced for real fabric, so that where the presser foot exits one of the seams, it encounters the other seam, which has the same thickness. There is no change of height, and the presser foot glides smoothly.

When sewing, stitch as closely as possible to the inside of the hem. As the needle reaches the intersection of the two hems, begin a smooth curve toward the extreme corner of the work. This will secure the little pocket of fabric where the two hems meet. Now that pocket can't get caught on anything during everyday use. When the needle reaches the extreme corner, lift the presser foot and turn the work, to begin a smooth curve down to the inside edge of the remaining hem. This will result in a leaf or petal shape on the outside of the work. It is a decorative finish that has a practical purpose. It is fun to experiment with different leaf shapes.

Practicing with our paper, we can use a stapler in place of the sewing machine. We staple as closely as we can to the inside edge of the hem, and then we practice the curve and the turnaround at the tip.

We can practice this construction with paper as many times as we need to before we take on the sometimes intimidating task of sewing our fabric. It's nice to make our mistakes on a less-precious material. This is a good idea for beginner sewists and for experienced people who might tend to be overconfident.

It never hurts to take a step back and think it through all the way. Most of sewing is preparation.

It's remarkable how quickly we can stack up six layers of fabric when we start with only one. We fold our frayed edge, and then we fold it again to cover itself. That puts two layers on top of the original layer, making three. At the corner we are folding one hem over another hem. That puts three layers on top of three layers, so we have six.

Not only is this much thicker than our one orignal layer, but it is also unbalanced. As we sew toward our corner, we are piercing three layers. Suddenly our presser foot crashes into a wall of three new layers, and that wall wants to fall away from the presser foot. If our presser foot manages to climb that wall, the fabric will probably be pushed out of alignment. Then our needle, piercing six misaligned layers, may be pushed so far that it strikes the needle plate and breaks.

One way to solve this problem is to stop overlapping one hem onto the other hem. Instead, we can bring them together end-to-end, at a 45 degree angle. This is called a miter or mitre.

Download this PDF to get started.

We can practice this with a piece of paper. We fold each edge twice, creasing the paper, to make our usual hems. Now if we unfold the paper we can see where the finished corner will be, where the innermost creased lines meet. We fold across that corner at a 45 degree angle, so that the tip of the paper is pointing toward the middle of the page. This dog-ear fold crosses both hems.

Now, we are going to cut away most of this corner, but we want to stay away from where our finished corner will be. If we cut exactly across that finished corner, then we will have ragged threads protruding from our garment. We want to protect that corner. Move the scissors out. Look at the width of one of the folds and move the scissors about that far. Now cut off the corner.

Fold down the remaining tab. Keeping that tab pressed down, fold each of the seams back into place. Now see that the two seams meet end-to-end, along a clean angle. The maximum number of layers is now four, where each of the folds overlaps the little tab.

The arrangement is well balanced for real fabric, so that where the presser foot exits one of the seams, it encounters the other seam, which has the same thickness. There is no change of height, and the presser foot glides smoothly.

When sewing, stitch as closely as possible to the inside of the hem. As the needle reaches the intersection of the two hems, begin a smooth curve toward the extreme corner of the work. This will secure the little pocket of fabric where the two hems meet. Now that pocket can't get caught on anything during everyday use. When the needle reaches the extreme corner, lift the presser foot and turn the work, to begin a smooth curve down to the inside edge of the remaining hem. This will result in a leaf or petal shape on the outside of the work. It is a decorative finish that has a practical purpose. It is fun to experiment with different leaf shapes.

Practicing with our paper, we can use a stapler in place of the sewing machine. We staple as closely as we can to the inside edge of the hem, and then we practice the curve and the turnaround at the tip.

We can practice this construction with paper as many times as we need to before we take on the sometimes intimidating task of sewing our fabric. It's nice to make our mistakes on a less-precious material. This is a good idea for beginner sewists and for experienced people who might tend to be overconfident.

It never hurts to take a step back and think it through all the way. Most of sewing is preparation.