The Basic Knot for Ending a Seam
A sewing knot is a small, tight loop you create at the end of your thread to keep stitches from unraveling. The most common method is the backstitch knot: take your needle to the back of the fabric, bring it up through the loop of thread you just created, and pull tight. This locks the thread in place without adding bulk to your seam.
The knot should sit right at the edge of your fabric or just inside the last stitch. If you tie it too far from the seam, it can slip through loose fabric and come undone. If you tie it too close to the needle, you risk creating a lump that shows on the front of your garment.
Key Takeaways
- The backstitch knot is the standard method: take your needle to the back of the fabric, loop the thread, and pull the needle through the loop to lock it.
- Tie your knot at the very edge of your seam or just inside the last stitch to prevent it from slipping through the fabric.
- A properly tied knot should be small and tight, with no loose thread tails hanging from the seam.
- Practice on scrap fabric first so you can feel how tight the knot should be before working on a real project.
- If your knot comes undone, you can tie a new one by bringing your needle back through the last few stitches and repeating the process.
Step-by-Step: The Backstitch Knot Method
Start by taking your needle to the back of the fabric after you have completed your final stitch. Leave about a quarter-inch of thread between the fabric and your needle.
Bring your needle back up through the fabric right next to where it went down, but this time pass it through the loop of thread you created. Pull the thread tight. You should see a small knot form at the base of that loop. Repeat this process one more time for extra security, especially on seams that will get heavy use.
Trim any loose thread tail with scissors, cutting as close to the knot as you can without cutting the thread itself. The knot should be invisible from the front of your fabric.
The Buried Knot for Invisible Seams
If you are working on a visible seam or a delicate fabric where even a small knot might show, you can hide the knot inside the seam itself. After your final stitch, bring your needle up through the fold of fabric along the seam line rather than through the back.
Run your needle inside the fold for about half an inch, then bring it back out. Pull the thread tight so the knot gets buried inside the fold. This method takes a bit more practice but leaves no visible knot on either side of the fabric. It works especially well for closing pillows, stuffed animals, or hems where you want a completely seamless finish.
Common Mistakes That Cause Knots to Fail
The most frequent problem is tying the knot too loosely. If you do not pull hard enough when you draw the thread through the loop, the knot will not hold. Test your knot by gently tugging on the thread—it should not slip at all. If it does, untie it and try again with more tension.
Another mistake is tying the knot too far from the fabric. Thread can slip through loose weaves, especially in cotton or linen. Always tie your knot right at the edge of your seam or just inside the last stitch. On very loose fabrics, you may need to take an extra backstitch before tying the knot to anchor it more securely.
Leaving a long thread tail after you tie the knot is also a problem. Loose threads catch on things and can pull the knot undone. Always trim your thread as close to the knot as possible, but be careful not to cut the knot itself.
Practicing on Scrap Fabric First
Before you tie off a knot on a project you care about, spend five minutes practicing on scrap fabric. Use the same type of fabric as your project if you have it—a knot on heavy canvas behaves differently than a knot on silk.
Tie at least ten knots in a row, pulling the thread tight each time and trimming close. You will develop a feel for how much tension is needed and where the knot should sit. Once you can tie a knot that does not slip when you tug on it, you are ready to use the technique on your actual sewing.
What to Do If Your Knot Comes Undone
If you notice a seam unraveling after you have finished sewing, you can fix it without starting over. Bring your needle back through the last few stitches of the seam, going backward toward the knot that failed. Take a new backstitch and tie a fresh knot using the method described above.
This repair works best if you catch the problem early, before more than an inch or two of stitching has come loose. On garments that get heavy wear, consider tying two knots instead of one—the extra security is worth the few seconds it takes.
Knot Variations for Different Fabrics
Delicate fabrics like silk or chiffon sometimes show even a small knot. For these materials, the buried knot method works better than the backstitch knot. You can also try taking an extra stitch or two before tying the knot, which spreads the tension over a larger area and makes the knot less likely to pull through.
Heavy fabrics like denim or canvas hold knots very securely, so a single backstitch knot is usually enough. On stretchy fabrics like jersey or spandex, take an extra backstitch before tying the knot because the fabric can shift and loosen the knot over time.
Frequently Asked Questions
How tight should I pull the thread when I tie the knot?
Pull hard enough that the knot does not slip when you tug on the thread with your fingers. It should feel snug and find, but not so tight that you are straining the fabric or breaking the thread. If the fabric puckers around the knot, you are pulling too hard.
Can I use a regular knot instead of a backstitch knot?
A regular knot (like tying your shoes) is too bulky for sewing and will show through thin fabrics. The backstitch knot is smaller and flatter, which is why it is the standard in sewing. Stick with the backstitch method for the best results.
What if the thread keeps slipping through the fabric when I tie the knot?
Your fabric is too loose or your knot is too far from the seam. Try tying the knot right at the edge of the fabric, or take an extra backstitch before tying to anchor it better. You can also try the buried knot method, which hides the knot inside the seam where it cannot slip through.
Do I need to tie a knot at the beginning of a seam too?
Yes. Start by tying a knot at the end of your thread before you begin sewing, using the same backstitch knot method. This prevents stitches from coming loose from the other end. Some sewers prefer to start with a few backstitches instead of a knot, which also works well.
How close can I trim the thread to the knot without cutting it?
Trim as close as you can see—usually about one-eighth inch from the knot. If you cut too close, you risk cutting the knot itself and undoing all your work. It is better to leave a tiny bit of thread showing than to accidentally cut the knot.