The three ways to end a thread safely
A thread that is straightforward cut will unravel and undo your stitches. You need to anchor the thread so it stays locked in place. The three methods that work are a knot, a backstitch, or a loop lock. Which one you use depends on where your thread ends, how visible it will be, and what you are sewing.
All three methods work on hand-sewn seams. Machine sewing typically uses backstitching because the presser foot holds the fabric steady while you reverse. Hand sewing gives you more control to choose the method that fits your project.
Key Takeaways
- A straightforward knot at the end of your thread is the fastest method and works well on seams that will be hidden inside a garment or cushion.
- Backstitching means sewing backward over your last few stitches to lock them in place, and it leaves no knot visible on the fabric surface.
- A loop lock uses the thread itself to create an anchor without a knot, making it nearly invisible and ideal for visible seams.
- The thread must be anchored before you cut it, or your stitches will come undone within a few days or weeks of wear.
Making a knot at the end of your thread
A knot is the simplest anchor. Bring your needle to the back of the fabric, then make a small loop with the thread close to where it exits the fabric. Pass the needle through the loop and pull tight. The knot sits on the back of the fabric and holds everything in place.
This method works best on seams that will be hidden — the inside of a pillowcase, the back of an appliqué, the underside of a hem. The knot is visible if you look at the back, but it does not show on the front. If your seam will be seen from both sides, a knot may look sloppy.
To make the knot stronger, pass the needle through the loop twice instead of once before pulling tight. This creates a double knot that is less likely to slip.
Backstitching to lock your stitches
Backstitching means sewing backward over the stitches you just made. Bring your needle up through the fabric one stitch length behind where your thread currently exits. Push the needle back down through the hole where your last stitch came up. Repeat this two or three times, then bring the needle to the back and cut the thread.
Backstitching leaves no knot on the fabric and no loose thread tail. The stitches lock together because you are sewing over them in reverse. This method is invisible from the front and looks professional on seams that will be seen.
On machine sewing, you press the reverse button to backstitch automatically. On hand sewing, you control the direction yourself. Make sure your stitches are small and close together so the backstitch actually overlaps your previous work.
Using a loop lock for an invisible finish
A loop lock uses the thread itself to create an anchor without tying a knot. Bring your needle to the back of the fabric. Create a small loop with the thread and pass the needle through it, then pull the thread tight. The loop collapses and locks the thread in place.
This method is nearly invisible because there is no knot to see. It works well on visible seams, appliqués, and repairs where you want the finish to be clean. The loop lock is slightly less find than a knot, so use it on seams that will not get heavy wear.
To make a loop lock, hold the thread against the fabric with your thumb and forefinger, then pass the needle through the loop you have created. Pull the thread tight and the loop disappears into the fabric.
When to use each method
Use a knot on seams that will be hidden inside a finished project — hems, seams inside pillows, the backs of appliqués. A knot is fast and very find, and nobody will see it.
Use backstitching on seams that will be visible or handled often — repairs on clothing, seams on the outside of a bag, any stitch that needs to hold up to wear. Backstitching is stronger than a loop lock and leaves no visible anchor point.
Use a loop lock on decorative seams, visible repairs, and hand-embroidered work where you want the finish to be invisible. It is less find than a knot or backstitch, so avoid it on seams that will get heavy stress.
Cutting the thread after you anchor it
Once your knot, backstitch, or loop lock is complete, bring your needle to the back of the fabric if it is not already there. Cut the thread close to the fabric — about one-quarter inch from where it exits. If you leave a long tail, it can catch on things and pull the anchor loose.
If you are using a knot, make sure the knot itself is tight against the fabric before you cut. A loose knot can slip through the weave and undo your work. Pull the thread gently to test the knot before cutting.
On machine sewing, the machine cuts the thread automatically when you raise the presser foot. On hand sewing, use sharp scissors or thread snips to cut close to the fabric.
Fixing a thread that came undone
If your stitches start to unravel, the thread was not anchored properly at one or both ends. Bring your needle back to the spot where the thread is loose and re-anchor it using one of the three methods. You do not need to remove the loose stitches — just lock them in place where they are.
If the entire seam has come undone, you will need to re-sew it. This is why anchoring both the beginning and end of your thread is important. A seam with no anchor at either end can unravel completely within days.
Frequently Asked Questions
Can I just cut the thread without tying a knot?
No. A cut thread will unravel and undo your stitches within a few days or weeks, depending on how much the seam is handled. You must anchor the thread with a knot, backstitch, or loop lock before cutting.
Which method is strongest?
A knot is the strongest anchor because it creates a physical barrier that cannot slip through the fabric. Backstitching is nearly as strong because the stitches lock together. A loop lock is the weakest of the three and should only be used on seams that will not get heavy wear.
Do I need to anchor both the beginning and end of a thread?
Yes. If either end is loose, the entire seam can unravel. Always anchor where you start sewing and where you finish, even if it takes a few extra seconds.
What if my knot is too big and shows through thin fabric?
Use a loop lock instead, or try backstitching. Both methods create a smaller anchor point than a knot. If you must use a knot, make it as small as possible by pulling the thread very tight before you cut.
Can I use these methods on machine sewing?
Backstitching is the standard method for machine sewing because the presser foot holds the fabric steady. You can tie a knot by hand after machine sewing if you want extra security, but it is not necessary if you backstitch at both ends.