The Basic Method: Tie a Knot and Keep Going

The simplest way to switch yarn is to tie the new yarn directly to the old one with a square knot, then continue knitting. Cut the old yarn about 6 inches from your needle, cut the new yarn the same length, and tie them together using a square knot — right over left, then left over right. Tighten it firmly, then weave the loose ends into your finished fabric with a tapestry needle once you're done knitting.

This method works best when you're switching colors for a stripe or block of color, because the knot sits inside your fabric where it won't show. It's fast and requires no special technique. The downside is that the knot can sometimes come loose if you pull the yarn too hard while knitting the first few stitches after the switch, so tension matters.

If the knot does slip, you'll see the old yarn poke through. To prevent this, knit the first stitch after the knot loosely, then tighten up your tension on the second stitch. Some knitters tie a second knot as backup, though one tight knot is usually enough.

Key Takeaways

  • A square knot tied between the old and new yarn is the fastest method and works well for color changes within your project.
  • Weave the loose ends into your finished fabric with a tapestry needle after you're done knitting to hide them completely.
  • The Russian join method creates a nearly invisible seam by threading yarn through itself and works best on smooth, non-fuzzy yarns.
  • Felting the ends together by wetting and agitating them works only on animal fibers like wool and creates a permanent bond.
  • Your choice depends on yarn type, where the join sits in your project, and how much time you want to spend on finishing.

The Russian Join: Threading Yarn Through Itself

The Russian join hides the connection almost completely by threading the new yarn through the old yarn's fibers. Thread the old yarn onto a tapestry needle, insert the needle through the new yarn about 2 inches from the end, and pull it through. Then thread the new yarn onto the needle, insert it through the old yarn the same way, and pull tight. The two yarns are now locked together without a knot.

This method works best on smooth, medium-weight yarns where the fibers grip each other. It fails on fuzzy or textured yarns because the fibers won't hold. It also doesn't work well on very thin yarn, where there aren't enough fibers to thread through. Test it on a scrap first if you're unsure.

The Russian join takes longer than a knot but produces a nearly invisible seam. It's ideal when the join will sit in a visible spot, like the middle of a stripe or the edge of a colorwork pattern. Once you've threaded both directions, trim the ends close to the yarn and they'll disappear into the fabric.

Felting the Ends Together for Wool

If you're working with wool or another animal fiber, you can felt the old and new yarn together by wetting them, overlapping them, and agitating them until the fibers bond. Overlap the ends about 2 inches, wet them with warm water and a drop of dish soap, then rub them together between your palms or on a washboard for 30 seconds to a minute. The fibers will felt and lock together permanently.

This method creates the strongest join and leaves almost no bulk. The downside is that it only works on animal fibers — plant fibers like cotton and acrylic won't felt. You also can't undo it once the fibers have bonded, so it's a permanent choice. Test on a scrap of your actual yarn to make sure the colors don't bleed or change when wet.

Felting works especially well for projects where the join will be in a high-stress spot, like the middle of a sweater sleeve. Once the fibers are felted, you can trim the ends very short and they won't come loose.

Splicing: Unraveling and Overlapping Yarn Plies

Splicing works on multi-ply yarn by unraveling both the old and new yarn back about 2 inches, overlapping the individual plies, and twisting them together. Separate the plies of the old yarn and the new yarn, then overlap them so the plies from each yarn interlock. Twist gently to lock them in place, then trim any loose fibers.

This method creates almost no bulk and produces a very strong join. It works on any yarn with visible plies, from fingering-weight to bulky. The trade-off is that it takes time and requires steady hands. It's best for projects where the join will be visible and you want it to look intentional, like a color change in a striped sweater.

Splicing doesn't work on single-ply yarn or yarn where the plies are tightly twisted together. If you can't separate the plies easily, use a different method. Practice on a scrap first — once you get the feel for how much overlap you need, it becomes faster.

Where the Join Sits in Your Project Matters

A join that sits inside your fabric (like in the middle of a stockinette stitch section) can be bulky without anyone noticing. A join that sits at an edge or in a visible spot needs to be as invisible as possible. Think about where your color change or yarn switch will land before you choose your method.

If the join will be at the edge of your project, like the side seam of a sweater, you can use a knot because the seam will hide it anyway. If the join will be in the middle of a stripe, the Russian join or felting will look better. If the join will be at the very edge of a piece, like the end of a scarf, you might want to plan your yardage so the switch happens at a natural stopping point instead.

Some knitters also choose their method based on how much time they have. A knot takes 30 seconds. A Russian join takes 2 to 3 minutes. Felting takes about a minute plus drying time. Splicing takes 5 to 10 minutes. If you're on a important date, the knot is your fastest option.

Switching Yarn Mid-Project Without Stopping

You don't have to finish a row to switch yarn. You can tie on the new yarn in the middle of a row and keep knitting. The join will sit inside your fabric, hidden by the stitches around it. This is useful when you run out of yarn unexpectedly or when you're doing colorwork and need to switch colors mid-row.

To switch mid-row, straightforward tie the new yarn to the old yarn using a square knot, then continue knitting. The first stitch after the knot might be slightly loose, so tighten it up on the second stitch. Once you've finished the project, weave the loose ends in with a tapestry needle.

If you're doing colorwork (like stripes or Fair Isle), you can also carry the unused yarn up the side of your work instead of cutting it. This works if you're switching back and forth between the same two colors. Twist the unused yarn around the working yarn every few rows to keep it from creating long loops on the edge.

Preventing Weak Spots at the Join

The join is the weakest point in your yarn, so tension matters. After you tie the knot or complete the join, knit the first stitch loosely, then tighten your tension on the second stitch. This gives the knot room to settle and prevents it from pulling apart.

If you're worried about the join coming loose, you can tie a second knot as backup, though one tight knot is usually enough. Some knitters also weave the loose ends in when ready after tying the knot, before they continue knitting. This locks the knot in place and prevents it from slipping.

Once your project is finished, weave all loose ends into the fabric with a tapestry needle. Weave in one direction for about 2 inches, then reverse direction and weave back over the same path. This creates friction and keeps the end from coming loose. Trim any remaining yarn close to the fabric.

Frequently Asked Questions

Can I switch yarn in the middle of a row?

Yes. Tie the new yarn to the old yarn with a square knot and keep knitting. The join will sit inside your fabric where it won't show. Knit the first stitch after the knot loosely, then tighten up on the second stitch so the knot doesn't pull apart.

What's the difference between a square knot and a granny knot?

A square knot (right over left, then left over right) holds tight and won't slip. A granny knot (right over left twice, or left over right twice) can come loose. Always use a square knot when joining yarn. Test it by pulling hard on both ends — a square knot won't budge.

Will the knot show in my finished project?

Not if it sits inside your fabric. A knot hidden in the middle of stockinette stitch won't be visible. If the join sits at an edge or in a visible spot, use the Russian join or felting instead to make it less noticeable.

Can I use the Russian join on acrylic yarn?

The Russian join works best on smooth, natural fibers like wool and cotton where the fibers grip each other. It's harder on acrylic because the fibers are slippery. A square knot is more reliable for acrylic yarn.

How do I hide the loose ends after I tie the knot?

Thread the loose ends onto a tapestry needle and weave them into your finished fabric. Weave in one direction for about 2 inches, then reverse and weave back over the same path. This creates friction and keeps the end from coming loose. Trim any remaining yarn close to the fabric.