Corners get a bad rap. You get backed into them, things go wrong when you cut them, and when you’re bad, you have to stand in them. In sewing, when two exterior raw edges come together at 90˚, you’re faced with hemming around a corner. If you’ve always been fearful about what lurks around a hemmed corner, this is the tutorial for you. Today, we’ll show you the easiest ways to sew a corner hem. You’ll learn how to fold and sew the fabric at the corner of a hem so there is a diagonal seam from the point of the corner to inside the edge of the hem. The diagonal seam is the point of the miter, which is why this type of hem finish is sometimes referred to as a mitered hem. 

Sewing a corner hem is considered a professional level finish, but don’t let the word “professional” stop you in your tracks. It’s really quite simple; it just takes a few extra steps. Once you know those steps, you’ll be cornerin’ like an Indy race car driver! 

Where am I likely to sew a corner hem? 

Panel curtains or other types of window treatments: there is almost always a corner hem at the bottom corner edges. If the curtain is lined, the lining is sewn separately and is shorter than the hemline so as not to interfere with the corner hem process.

Table linens, such as placemats, tablecloths or napkins sewn with a single layer of fabric: a corner hem eliminates bulk in the corners, which aids in the function as well as the appearance of your finished item.

Garments, such as our famous Sew4Home aprons: corner hems also show up in slits on a skirt or vents in a coat. This is especially true if the garment is made of wool or other heavy weight fabric. If the garment has a lining, the lining is left unsewn at the corners, then is hand-tacked into place after the corner hem is completed. Use today’s technique on the three tiers of yesterday’s Michael Miller Cotton Couture shabby chic ombre apron!

Quilt bindings: because the main purpose of a corner hem is to eliminate bulk, this technique is a favorite among quilters to create beautiful bindings. 

Sewing a corner hem 

The easiest situation for a corner hem is when the side hem and bottom (or next side) hem are equal in depth. In some of the examples we listed above, like a slit in a skirt or the corners of a napkin, the depth of the hem is the same. However, there are always exceptions to the rule! In the case of panel curtains, the side hem is usually shorter in depth than the bottom hem. Therefore, there is a separate way to create a corner or mitered hem for this specific instance. Below, we show you both options. 

Equal hem depths

Before we get into the details of how to sew this corner hem, we want to make you aware of the hem allowance measurement. With this technique, you usually turn under the raw edge a small measurement (approximately ¼” to ⅜”), then turn the hem under again a set measurement to reach your finished length. Traditionally, this second measurement is equal to or larger than your first measurement. In our example, we turned under the raw edge ⅜”, then turned under the hem again 1″. If you’re following a pattern or tutorial, the instructions should guide you how to handle the hem allowance. If you’re creating something from scratch, just remember to keep the total hem allowance needed in mind before cutting the fabric.

1. Fold and press the side hem ⅜”. 
2. Fold and press the bottom (or next side) ⅜”. The second (bottom) hem will overlap the first (side) hem at the corner.
   
3. Fold and press the side hem again, this time by 1”. Then, fold and press the bottom (or next side) hem again, this time by 1”. As above, the hems will overlap at the corner. 
   
4. Unfold both hems to reveal the pressed lines. The point where the pressed lines intersect is where you will begin to sew the corner hem.
   
5. At this intersection, fold the fabric right sides together at a point. It should form a triangle. Place a pin at a 45° angle from the intersection, pointing towards the raw edge. 
   
6. Using a straight stitch, sew from the the pin point at the folded edge to the first pressed line. 
   
7. Lock your stitch at the beginning and end.
   
8. Trim the away excess ‘triangle’ to ¼” from the sewn seam. 
   
9. For an extra smooth corner, also trim away a tiny angle from the folded edge to the right of the seam. 
   
   NOTE: For more on sewing and clipping corners see our tutorial here. 
10. Press the seam open.
    
11. Following the previously pressed guidelines, fold the hems back into place, pushing out the corner hem.  Pin the folded edges.
    
12. Sew with a straight stitch, or the decorative stitch of your choice, close to the inside fold.
    
    NOTE: If you are brand new to this technique, we recommend you baste the corner hem seam first, before final sewing and cutting. And, as we always suggest, practice first on scraps.

Unequal hem depths

Unlike the equal hem depth example above, this bad boy is a little trickier and takes a bit of fussing to get the miter just right. For our sample, we are pretending to hem the corner of a drapery panel where the bottom hem is much deeper than the side hems. Our side hem is 1″ and our bottom hem is 3″. However, as in the example above, in addition, we first press under the raw edge a small measurement; we used ¼”.

1. Fold and press the side hem ¼”.
2. Fold and press the bottom hem ¼”.  Again, the bottom hem will overlap the side hem.
3. Fold and press the side hem 1″.
4. Fold and press the bottom hem 3″.
   
5. With a fabric pen or pencil, mark the point where the inside edges of the two hems meet.
    
6. Unfold the hems to expose the marked point and the pressed lines. 
7. Pinch and fold the fabric right sides together to create a fold line that runs through the points of intersection indicated by the pressed lines. Press in place. 
   
   NOTE: If it helps you see, you can first draw a line from the marked point through the pressed points of intersection, then pinch, fold and press along the drawn line.  
   
8. Refold the raw edge ¼”, following the original pressed line. 
9. Fold the corner to inside the point of intersection. The top folded edge will be perpendicular to the drawn/pressed angled line you just made.
   
   NOTE: As we mentioned above, you may have to fuss with this fold, and do it more than once, to get the angle just right. 
10. Starting at the side hem, fold in the fabric at an angle to meet at the marked point. Pin in place. Again, you may have to try this a few times to get the fold just right.
    
11. Fold up the bottom hem, so it also meets perfectly at the marked point and creates a mitered angle. Pin in place
    
12. With a large miter like this, it’s a good idea to hand stitch along the miter to help hold the angles in place.
    NOTE: As always, we are using a light fabric and contrasting thread to insure you can see and follow along with our steps. In real life, you’d use matching thread for your fabric to stitch the miter closed. 
    
13. As above with the equal depth hems, using a straight stitch, sew along the inside fold to secure and complete.

Raw edge finishing option

In our examples above, we opted to turn under the raw edges of the fabric along the hems. However, you can also finish the raw edges of your fabric first, before creating the corner hem, using a zigzag stitch on your sewing machine or an overlock stitch on your serger. Our photo shows a serged edge. 

Other than finishing the edge first, all the remaining steps are exactly the same. You can use the serging itself as a guideline to sew around the hem once the corner hem has been completed. 

Pressing 

If you are a S4H regular, you know we are passionate about pressing! It is a key component in most sewing techniques and corner hems are no exception. You rely on your pressed lines to know where to start and stop sewing, as well as where to create the mitered point on an unequal hem allowance. You must be very precise with your pressing in order for the points of intersection to be accurate.

In addition, as we stated earlier, one of the main reasons for creating a corner (or mitered) hem is to eliminate bulk. If you’re using a bulky fabric, you need to be cautious about leaving a pressing imprint on the right side of your fabric. Place a piece of heavy paper, cardboard or a metal hem gauge between the hem and the fabric to prevent unwanted imprinting.

Quick tip cousin

For narrow hems of equal depth on lightweight fabrics, check out our clever folding-and-pressing-only tutorial. Not a true miter, but still super cool.

Clean Corners on Narrow Hems

Sample Creation and Instructional Outline: Jodi Kelly