A few tips on sewing corners can make the difference between a garment that looks homemade and a garment that looks handmade.
And I know you want the latter, of course. (Lumpy, rounded corners are not the look.)
In this article you will learn:
- How to sew the three types of corners (with photos!)
- What are the best tools for turning sharp points
- How to masterfully topstitch corners
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Types of Corners to Sew
In sewing, you’ll encounter three corners: inside, outside, and mitered. These corners can be at any angle, acute (less than 90 degrees) to obtuse (more than 90 degrees). Let’s explore how to sew corners that will make your garments look totes profesh*.
*Highly technical term, obvs.
For your reference, a squared-off neckline is one place you’d see inside corners.
Picture a capital letter “L.” If this “L” were an inside corner, its left side (and lower) would be fabric).
Here’s how to sew your best-ever inside corners.
1.) At the corners of both pieces of fabric, fuse a small square of interfacing that covers the seam allowance between the fabric edge and pivot point.
- Don’t let it extend (much) beyond the seam (maybe ⅛ inches).
- This keeps the corner from stretching or fraying.
- Match the interfacing to the fabric. If you’re questioning which IF to use, lighter IF is better than heavy IF.
2.) Mark the pivot point (this will be atop the interfacing), and maybe draw a line a centimeter or two before and after the pivot point. Guides are your friends!
3.) Sew toward the pivot point, shortening stitch length as to not overshoot the pivot.
4.) Sink the needle in the pivot point. Lift the presser foot.
5.) Rotate the fabric with the needle sunk in the fabric. Drop the presser foot (important!), and lengthen the stitch (if necessary). Continue sewing.
6.) Find your sharpest scissors (sharp scissors make this next bit easier and more precise). Snip from the corner fabric edge to, but not through, the pivot point.
- This snip helps the fabric in the corner lay flat and smooth.
7.) Grade the seam allowance, trimming the seam allowance that will be closest to your body to about ¼ inches.
- Reducing bulk when you have to turn fabric right-side out is always encouraged.
8.) Turn right-side out. Use your hands, fingers, fingernails, and turning tools (see “Tools for Sewing Corners below) to flatten and sharpen the corner.
9.) Press the seam and corner with a press cloth.
Outside corners are the corners you see at the point of a dress-shirt collar.
Again, picture that capital letter “L.” If this “L” were an outside corner, its right side (and up) would be fabric.
Here’s how to approach sewing outside corners. A lot of this instruction overlaps with sewing inside corners. But, there are some critical differences.
1.) On the wrong side, mark the pivot point and a centimeter or two before and after the pivot point.
2.) Sew toward the pivot point, shortening stitch length as to not overshoot the pivot.
3.) Sink the needle in the pivot point. Lift the presser foot.
4.) Rotate the fabric about half the full pivot. For example, if you were sewing a 90 degree angle, you’d rotate the fabric 45 degrees.
5.) Drop the presser foot. If you’re sewing light-to-medium weight fabric, sew one stitch on the diagonal. If you’re sewing heavyweight fabric, sew two stitches on the diagonal.
- You are flattening the point of the corner.
- The flattened corner on the inside (wrong side) gives the seam allowance room to spread out, which removes bulk from the corner. The result is a sharper corner. It seemed counterintuitive to me at first, but I swear it works!
6.) Again sink the needle in the fabric. Lift the presser foot.
7.) Rotate the fabric the rest of the way to complete the full corner angle. Drop the presser foot (important!), and lengthen stitch (if necessary). Continue sewing along the other edge.
8.) Grade the seam allowance, trimming the seam allowance that will be closest to your body to about ¼ inches.
9.) Cut off the top of the corner, leaving about ⅛ inches seam allowance.
- This trim happens above the “flattening” stitches.
10.) Cut away more seam allowance. Place the tip of your scissors on the edge of the seam allowance about one inch from the corner. Trim toward the corner, blending into the ⅛ inches seam allowance above the flattening stitches.
- Do this for both edges of the corner.
- We’re removing still more bulk from the corner to make the corner as flat and smooth as possible.
11.) Turn right-side out. Use your hands, fingers, fingernails, and turning tools (see “Tools for Sewing Corners” below) to flatten and sharpen the corner.
12.) Press the seam and corner with a press cloth.
Mitered corners are the “fancy” corners with a diagonal seam. In the non-garment-sewing world, you sew them on quilts and cloth napkins.
You can read an article about how to sew mitered corners of unequal lengths — where the two folded edges coming together are unequal measurements (e.g., one fold is one-quarter inches and the other fold is one-half inches).
In THIS article, however, we’re covering how to miter corners of EQUAL lengths (e.g., both folds are one-half inches). This mitering technique works with corners of ANY angle.
0.) Finish the raw edges as desired — serged, folded, etc. These instructions assume the edges are finished and the next step is finishing the corner with a miter. (P.S. Pretend the edges of the fabric in the photos are finished, m’kay? Tx.)
1.) Fold the first edge, wrong sides touching, and make a pronounced crease. Unfold.
2.) Fold the second (opposite) edge, wrong sides touching, at the same width and make a pronounced crease. Unfold.
3.) Using a marking tool, draw a line on the wrong side from the outer corner point, through the intersecting creases, and approximately twice the width of the folds.
- You need to be able to see this diagonal line when the edges are folded to the wrong side.
4.) Fold the first edge on the crease, wrong sides together.
- The first edge now overlaps the diagonal line drawn in Step 3.
5.) Make a tiny mark on the first edge where it meets the diagonal line. (The mark is on the right side of the fabric.)
6.) Unfold the first edge. Transfer the diagonal line mark on the right side to the wrong side.
7.) Draw a line from the transferred diagonal line mark (Step 6) to the fold intersection.
8.) Repeat steps 4 through 7 with the second edge.
9.) With right sides together, fold the to-be-mitered corner on the line that runs from the outer corner edge through the intersection.
10.) Time to sew the miter. With the corner still folded, stack the lines drawn in Step 7. This is the stitching line.
11.) Pin the layers of fabric together to hold this fold.
12.) Stitch on the line you drew in Step 7, from the fold to the outer edge. Congrats, you sewed a miter!
13.) To check your work, turn the corner right-side out (wrong sides touching) and gently work it into position. If you did the miter correctly, it will be obvious.
14.) Fold the miter wrong side out. Trim off the excess seam allowance above the miter stitching line, leaving about one-eighth to one-quarter inches of seam allowance.
15.) Using a turning tool (see “Tools for Sewing Corners” below), your hands, fingers, and fingernails, flip the miter so that the right side is out and the wrong sides are touching. The corner should be smooth and flat and sexy (IMHO mitered corners are sexy).
16.) Press the mitered corner, slipping a press cloth or an envelope inside the mitered corner (where the wrong sides are touching).
- This prevents the miter from making an impression on the outside of the garment when you hit it with the iron.
Tools for Sewing Corners
The final steps in sewing a super-sharp corner — turning and pressing — require tools. Consider the following sewing supplies for these tasks:
Does what it says. A point turner is about 6 inches long with a pointed end. It can be plastic or wood; I like wood because you can use it with an iron.
Knitting Needle / Chopstick / End of a Makeup Brush Handle
A pointy wood stick implement here is better than a metal one, because wood tends to be blunter and less likely to poke through the corner. (You always can wrap a metal implement with a little fabric, batting, or tape to blunt a sharp tip.)
Tailor Board with Point Presser
The point presser part of a tailor board is made specifically for turning out sharp collar corners.
EZ Point and Turner
This turning tool, which is reminiscent of science lab tongs to hold a beaker, has one tip with a blunt end (for holding an inside-out fabric pocket) and one tip with a pointed end (for turning out sharp corners). It’s a slick tool that’s kind of hard to explain; see how it works in this video (time code 16:35 to 17:44).
Set that sharp corner with heat.
Protect the fabric from too much heat.
This is a piece of hardwood to smack on the corner after it’s pressed. The clapper absorbs steam and sets creases as the fabric cools. (P.S. A tailor board usually includes a clapper.)
After you sew corners in a garment, sometimes you have to topstitch them, too. Here are some tips on how to topstitch corners of any degree like a boss.
Topstitching with a Straight Stitch
1.) Mark the Turn
Don’t guess where to pivot. At the very least, use a marking tool to mark where the pivot is located. Bonus points for giving yourself a centimeter on either side of the pivot so the corner is basically guaranteed to be foolproof.
2.) Shorten Stitches
As you approach the pivot, reduce the stitch length. This way you won’t overshoot the pivot with a stitch that’s too long, and you can continue sewing with a line of stitches that’s the same distance from the edge all the way around.
Just don’t forget to go back to the original stitch length after the pivot.
It should go something like as you approach the pivot…
Regular Stitch →
Shorter Stitch →
Sink Needle at Pivot Point →
Lift Presser Foot →
Pivot Fabric →
Drop Presser Foot →
Reset to Regular Stitch →
Continue Stitching on Other Side of Corner
Topstitching with a Zig-zag (Lateral) Stitch
1.) Mark the Turn
It’s such a good tip, it bears repeating. Mark the pivot point and let your topstitching be equidistant from the edge on all sides.
2.) Shorten Stitches
Yet another tip worth an encore. Shortening a zig-zag stitch makes it look more dense; it’ll be more obvious that something changed about the topstitching (vs. shortening a straight stitch, which can be almost imperceptable).
So, with that in mind, practice your lateral-stitch topstitching on scrap fabric to come up with settings and whatnot that look best to you.
And if you shorten the length, remember to return to the original length after you turn the corner.
3.) Don’t Forget Needle Position and Stitch Density
When you get to the pivot point while sewing with a zig-zag or other lateral stitch, you will need to make a choice about whether to pivot on the left stitch or the right stitch.
Whether you go for the left or go for the right is a matter of preference; you’re the designer.
Sometimes you see lines of zig-zag stitches significantly overlap at a corner vs. a cleaner pivot and turn. Again, it’s your choice, but think about stitch density at the corner. Ask yourself:
- Is this the look I want?
- Will my machine rebel sewing over a stack of dense, lateral stitches? (This feels like you’re asking for a bird’s nest.)
Final Thoughts on How to Sew Corners in Garments
Sewing corners is a technical feat, to be sure. But, with your favorite marking tool, point turner, and the right method, your corners will be sharp enough to cut glass (if only!).
Don’t back down from learning how to sew corners. Corners truly are a feature that can make a garment look homemade vs. handmade. And, we’re all about that bespoke sewing life at Sie Macht.