The Weaver's Knot Works for Most Projects

The simplest way to add more yarn is the weaver's knot, which ties the old yarn to the new yarn with a knot that sits flat against your work. You make two small loops—one from each yarn end—thread one loop through the other, pull tight, and trim the tails. The knot stays on the back of your fabric and disappears into the texture of most stitches. This method works on any yarn weight and takes about 30 seconds once you know the motion.

To tie a weaver's knot, hold the old yarn in your left hand and the new yarn in your right. Make a small loop with the old yarn, pinching it between your thumb and forefinger. Pass the new yarn up through that loop from underneath, around behind the old yarn loop, and back down through the loop. Pull both ends of the new yarn tight—the old yarn loop will cinch around it. Then pull the old yarn tight as well. The knot tightens into a small, flat square that won't unravel.

The main drawback is that you have two short tails to weave in later, one from each yarn. If you're working a project where the back will show—a blanket you'll see from both sides, or a scarf—you might prefer a method that hides the join better.

Key Takeaways

  • The weaver's knot ties old and new yarn together with a flat knot that sits on the back of your work and disappears into most stitches.
  • The Russian join lets you thread new yarn through the old yarn's fibers without a knot, leaving almost no bulk and only one tail to weave in.
  • Splicing works only on wool and other animal fibers—you wet the yarn ends and rub them together until the fibers bond permanently.
  • Always join yarn at the beginning of a row rather than in the middle of a stitch, so the join sits at the edge where it's easiest to hide.
  • Test any join method on a practice swatch first to see how visible it is in your stitch pattern and yarn color.

The Russian Join Hides the Connection Almost Completely

The Russian join (also called the invisible join) threads the new yarn through the fibers of the old yarn without tying a knot at all. This method leaves almost no bulk and only one tail to weave in, making it ideal for projects where both sides will show. It works best on yarn thicker than fingering weight—very thin yarn is harder to thread through.

Thread the old yarn through a tapestry needle, then push the needle through the center of about 2 inches of the new yarn, splitting the fibers as you go. Pull the old yarn through, leaving a small loop. Now thread the new yarn through the same tapestry needle and push it through the center of the old yarn the same way. Pull the new yarn through, and the two yarns will be locked together. Trim the old yarn close to where it exits the new yarn, and trim the new yarn close to where it exits the old yarn. The ends will stay hidden inside the yarn itself.

This join is nearly invisible in the finished fabric, but it does create a slightly thicker spot where the two yarns overlap. In a textured stitch like garter or seed stitch, this thickness disappears. In stockinette, you might see a tiny bump. Test it on a swatch in your actual yarn and stitch pattern before committing to it on a large project.

Splicing Works Permanently on Animal Fibers

Splicing is a method that bonds two yarn ends together by rubbing wet fibers until they fuse. It works only on wool, alpaca, mohair, and other animal fibers—not on cotton, acrylic, or plant-based yarns. When done well, the splice is completely invisible and creates no knot or bulk at all.

Overlap about 2 inches of the old and new yarn. Wet both overlapped sections with warm water and a drop of dish soap. Rub the wet fibers between your palms or on a towel with firm, steady pressure for 30 to 60 seconds. The friction and moisture cause the scales on the animal fibers to open and lock together. Once the fibers have bonded, rinse the splice under cool water and let it dry completely. The join will be as strong as the yarn itself.

Splicing takes longer than other methods and requires the right yarn fiber, but it produces the most seamless result. Many knitters use it only for projects where the join will be very visible, like a color change in a striped sweater. Practice on scrap yarn first—the motion takes a few tries to get right, and if you rub too gently, the fibers won't bond.

Timing: When to Join Yarn During Your Row

The best moment to join new yarn is at the beginning of a row, not in the middle of a stitch. When you reach the end of a row and have only a few inches of yarn left, finish that row and cut the old yarn. Start the new row with the new yarn, tying or joining it to the old yarn at the edge. This placement hides the join at the selvage (the edge of your fabric), where it's least visible.

If you run out of yarn mid-row, you can still join in the middle of a stitch, but the join will be more visible. Finish the stitch you're on, then tie or join the new yarn. The knot or splice will sit within the stitch itself rather than at a clean edge. For this reason, many knitters keep track of their yarn length and plan to finish a row before running out.

A straightforward way to check if you have enough yarn to finish a row: lay your remaining yarn alongside the row you're about to knit. If the yarn is at least three times as long as the row is wide, you have enough. If not, finish the current row and join at the edge instead.

Common Mistakes That Weaken the Join

The most common error with the weaver's knot is pulling too hard on one end before the knot is fully formed. The knot needs both ends pulled evenly—if you yank the old yarn before the new yarn is tight, the knot will slip and come undone. Pull the old yarn loop tight first, then pull both ends of the new yarn together, then pull the old yarn end. This order keeps the knot from sliding.

With the Russian join, the most frequent mistake is not threading far enough into the yarn. You need to go through at least 2 inches of the yarn's center fibers, not just the outer layer. If you thread only a short distance, the join will separate when you tug on it. Push the needle all the way through and pull the yarn completely through before moving to the next step.

For splicing, the biggest error is not using enough water or not rubbing long enough. The fibers need to be wet enough to open their scales, and the friction needs to be sustained for at least 30 seconds. If the splice feels weak after it dries, you didn't rub long enough. Wet it again and repeat the rubbing motion.

Testing Your Join Before You Commit

Before you use any join method on your actual project, knit a small swatch in your yarn and stitch pattern, then join yarn in the middle of it using the method you plan to use. Knit a few more rows, then tug hard on both sides of the join. A good join should not separate or slip. If it does, you know that method won't work for your yarn or you need to practice the technique more.

Also look at how visible the join is in your stitch pattern. In a dense stitch like ribbing, even a weaver's knot may disappear. In a loose stitch like lace, the same knot might be obvious. Testing on a swatch takes 15 minutes and can save you from having to rip out rows later.

Keep your test swatches. They become a reference guide for future projects in the same yarn—you'll know exactly which join method works best and how visible it is.

Frequently Asked Questions

Can I use the Russian join on acrylic yarn?

No. The Russian join works only on animal fibers like wool and alpaca, where the fibers have scales that can grip each other. Acrylic and plant-based fibers are smooth and won't hold the join. Use the weaver's knot instead.

Will the knot come undone if I tug on the yarn?

A properly tied weaver's knot will not come undone with normal tugging. If it slips, you didn't pull both ends evenly when tightening. Retie it, making sure to pull the old yarn loop tight first, then both ends of the new yarn together, then the old yarn end.

How short can the yarn tail be before I have to join?

You need at least 6 inches of yarn to tie a weaver's knot or thread a Russian join. If you have less than that, finish the row you're on and join at the edge. For splicing, you need about 3 inches of each yarn to overlap.

Do I have to weave in the tails after I tie a knot?

Yes. Even though the knot sits on the back, the short tails sticking out from the knot will unravel if you don't weave them in. Thread each tail through a tapestry needle and run it through several stitches along the edge, then trim close to the fabric.

What if I'm joining two different yarn colors?

Any join method works with different colors. The join itself will be visible at the color change no matter what method you use, so choose based on how much bulk you want. The weaver's knot creates a small knot; the Russian join creates almost no bulk; splicing (on animal fibers) is invisible.