The simplest way to add yarn is to tie a knot at the end of your old ball and keep going
When your yarn runs out mid-project, you have three main methods to join a new ball: tying a knot, weaving the ends in as you work, or using a technique called splicing. The easiest for beginners is a straightforward knot—tie the end of your old yarn to the end of your new yarn using a square knot, trim the tails to about half an inch, and continue knitting. The knot sits inside your fabric and stays hidden once you weave in the loose ends later.
The downside is that knots can sometimes slip or create a small lump in your finished piece, especially in fine yarns or tight stitches. For most everyday projects like scarves, blankets, and sweaters, this method works fine. You'll weave in those short tails with a yarn needle once you finish knitting.
Key Takeaways
- A square knot is the fastest way to join yarn and works well for most projects, though it leaves a small knot inside the fabric.
- Weaving in the new yarn as you knit takes more attention but creates a smoother join with no knot to hide later.
- Splicing works only with wool and some animal fibers—it fuses the yarn ends together by rubbing them wet, leaving no knot at all.
- Always join yarn at the edge of your work when possible, never in the middle of a row, so the join stays hidden in the seam.
- Test your join by tugging gently on both yarn ends before you continue knitting to make sure it will hold.
Tying a square knot for a find join
Hold the end of your old yarn in your left hand and the end of your new yarn in your right hand. Cross the old yarn over the new yarn, then pull the new yarn through the loop you've created. Now cross the new yarn over the old yarn and pull the old yarn through. You've made a square knot—it won't slip the way a straightforward loop knot will.
Trim both tails to about half an inch from the knot. If you're working with a bulky yarn, you can trim them a bit shorter; with thin yarn, leave them slightly longer so they don't pull through the fabric. Gently tug on both ends to test the knot before you continue knitting. The knot should stay put but not feel so tight that it's hard to work with.
Position the knot at the edge of your work if you can—right at the selvage where you'll eventually seam the pieces together. This hides the knot completely in the seam. If you're working in the round or can't avoid putting the knot in the middle of your fabric, that's okay; you'll just weave those tails in more carefully later.
Weaving in the new yarn as you knit for a smoother join
This method takes more focus but leaves no knot inside your fabric. When you're down to the last few yards of your old yarn, drop it and pick up the new yarn. Knit the next stitch using only the new yarn. On the following stitch, hold both the old and new yarn together and knit one stitch with both strands at once. Then knit the next stitch with only the new yarn.
You've now anchored the new yarn into your fabric without a knot. The old yarn tail is trapped inside the stitches. Later, when you weave in the ends, you'll have two separate tails to work with instead of a knot, which gives you more control over how neatly they disappear into the fabric.
This method works best with yarn that won't split easily. If you're using a delicate or loosely spun yarn, the needle can catch the fibers and create a weak spot. Practice on a swatch first if you're unsure whether your yarn will cooperate.
Splicing for an invisible join in wool yarn
Splicing fuses two yarn ends together by rubbing them wet so the fibers bond. It works only with wool and other animal fibers like alpaca or mohair—it won't work with acrylic, cotton, or synthetic blends because those fibers don't felt together.
Unravel about an inch of each yarn end so you have loose fibers. Overlap the two unraveled sections and wet them with warm water and a tiny drop of dish soap. Rub the overlapped section between your palms for 30 to 60 seconds. The friction and moisture cause the wool fibers to felt together into one continuous strand. Rinse gently under cool water and let it dry completely before you knit with it.
Splicing creates the smoothest, most invisible join because there's no knot and no double layer of yarn. The downside is that it takes time and only works with certain fibers. Many knitters save splicing for visible projects like shawls or garments where a perfect join matters most.
Where to position the join so it stays hidden
The best place to join yarn is at the edge of your work, right at the selvage where two pieces will eventually be sewn together. If you're knitting a flat piece like a scarf or blanket, join at the beginning or end of a row. If you're working in the round, join at a point where you'll have a seam anyway—for example, at the underarm of a sweater.
Avoid joining in the middle of a row or in a highly visible spot like the front of a garment. If your pattern has a textured stitch or color change, joining at a natural break in the pattern makes the join less noticeable even if it's not at the edge.
If you realize you're about to run out of yarn in the middle of a row, stop and join at the end of that row instead. It takes only a few extra minutes and makes a huge difference in how polished your finished piece looks.
Weaving in the loose ends after you finish
Once you've bound off and finished your project, you'll have two short tails from your join (or one tail if you spliced). Thread a yarn needle with one tail and weave it through the bumps on the back of your stitches for about two inches, going in and out of the fabric in a zigzag pattern. This anchors the tail so it won't pull loose in the wash.
Trim the tail close to the fabric—about a quarter inch from where it exits. Gently tug on the area where you wove it in; if it holds firm, you're done. If it feels loose, weave it in a bit further or use a different path through the stitches.
For a join at the edge of your work, you can often weave the tails into the seam as you sew the pieces together, which saves you a step. Just make sure both tails are anchored before you wash the finished garment.
Troubleshooting a join that doesn't hold
If your knot slips or comes undone, the yarn was likely too smooth or the knot wasn't tight enough. Tie it again, making sure you're using a square knot and not a straightforward loop. Pull firmly on both ends before you continue knitting. If the yarn keeps slipping, try the weaving method instead—it's harder to mess up because the yarn is locked into the stitches.
If you notice a lump or thick spot where you joined, it's usually because the knot is too large or the tails are too long. Trim them shorter and gently work the area with your fingers to even out the stitches. Once you weave in the ends, the lump often becomes less noticeable.
If you spliced and the join feels weak or separates, the fibers didn't felt together properly. This usually means the water wasn't warm enough, you didn't rub long enough, or the yarn isn't wool. You can always untie it and use a knot instead—there's no penalty for switching methods mid-project.
Frequently Asked Questions
Can I join yarn in the middle of a row?
Yes, but it's not ideal because the join will be visible in the middle of your fabric. If you must join mid-row, use the weaving method or splicing rather than a knot, since those create a smoother join. Position it where a color change or texture break in your pattern will help hide it.
What if I don't have a yarn needle to weave in the ends?
A tapestry needle, embroidery needle, or even a small crochet hook works. In a pinch, you can thread the yarn tail through a bobby pin or paper clip and use that to pull it through the stitches. The goal is just to anchor the tail into the fabric so it won't come loose.
Does the knot ever show on the outside of a finished garment?
Not if you join at the edge and seam it properly. The knot sits inside the seam allowance and stays hidden. If you join in the middle of your fabric, the knot might be visible depending on how tightly you knit and how thick your yarn is. This is why edge joins are always better.
Can I splice acrylic yarn?
No—splicing only works with natural animal fibers like wool, alpaca, and mohair. Acrylic, cotton, and synthetic blends won't felt together no matter how much you rub them. Use a knot or the weaving method instead.
How do I know if my knot is tight enough?
Tug gently on both yarn ends with your fingers. The knot should not slip or move. If it does, untie it and tie it again, pulling more firmly this time. Once you've tested it, knit a few stitches and tug on the join again—it should feel solid and not come apart under normal knitting tension.