The Basic Method: Weaving in the Old and New Ends

To start a new yarn, you stop knitting with the old yarn, leave a tail about 4 inches long, and begin knitting with the new yarn using the same tail length. The join itself is invisible because you weave both tails through the stitches on the back of your finished fabric later — a process called weaving in ends. This is the standard approach for most knitting projects and works whether you're changing colors, running out of yarn, or switching to a new ball of the same color.

The key is timing: you make the switch between complete stitches, never in the middle of one. Finish the stitch you're working on, drop the old yarn, pick up the new yarn, and knit the next stitch as normal. Your tension may be slightly loose or tight at the join for the first stitch or two — this is normal and evens out as you continue.

Key Takeaways

  • Cut the old yarn 4 inches from your work, then start the new yarn 4 inches from where you'll begin knitting, leaving tails on both sides of the join.
  • Make the switch between complete stitches, never mid-stitch, and knit the first stitch with the new yarn as you normally would.
  • Weave both tails through the backs of stitches on the wrong side of your fabric after you finish knitting to hide the join completely.
  • For color changes in stripes or patterns, tie a loose knot to hold the yarns together while you work, then untie and weave in the ends later.
  • If you're joining yarn in the middle of a row, the join will be less visible on stockinette stitch (smooth side) than on reverse stockinette or textured stitches.

Preparing Your Yarn Before You Start

Before you make the switch, make sure you have enough yarn left to finish your row or round. A good rule: if your remaining yarn is less than three times the width of your work, it's time to join a new ball. For example, if you're knitting a scarf 6 inches wide, you need at least 18 inches of yarn left to finish the row safely.

Cut the old yarn cleanly with scissors rather than breaking it by hand. A clean cut prevents fuzzy fibers from catching on your needles. Leave the 4-inch tail hanging from your work — don't pull it tight or weave it in yet. You'll handle both tails after your project is complete.

Joining the New Yarn Mid-Row

Position your needles so the working yarn (the yarn attached to your ball) is on the right side if you're right-handed, or the left side if you're left-handed. Drop the old yarn and pick up the new yarn, leaving a 4-inch tail. Knit the next stitch with the new yarn exactly as you would normally — no special technique, no knot, no twist.

The first stitch or two with the new yarn may look slightly loose compared to your other stitches. This is expected. Keep knitting, and the tension will even out within a few stitches. If the join is very loose, you can gently tighten it later when you weave in the ends.

Do not tie the old and new yarns together while you're knitting unless you're working a color pattern where both yarns will be used again in the same row (like Fair Isle). For a straightforward yarn change, a knot creates a lump that's hard to hide and can catch on your needles.

Joining Yarn at the End of a Row or Round

Joining at a row or round edge is often easier than joining mid-row because the join sits at the edge of your fabric, where it's less visible. Finish your row or round completely with the old yarn. On the next row or round, straightforward begin with the new yarn, leaving 4-inch tails on both sides.

If you're knitting in the round, the join will sit at the beginning of your round. This spot is usually less noticeable than a join in the middle of a visible row, especially if you're working a sweater or hat where the edge will be seamed or finished.

Weaving in the Tails to Hide the Join

After you bind off and finish your project, thread each tail (old and new) onto a yarn needle — a blunt needle with an eye large enough for your yarn. On the wrong side of your fabric, weave the needle through the backs of 4 to 6 stitches in a straight line, staying inside the same column of stitches if possible. This anchors the tail and hides it completely.

For the old yarn tail, weave it backward (toward the edge where you cut it) for about 4 stitches. For the new yarn tail, weave it forward (away from the join) for about 4 stitches. This spreads the join across a small area and prevents a visible bump. Trim any remaining tail close to the fabric.

If you're working with a stretchy yarn like mohair or a delicate yarn like lace-weight, weave the tails through more stitches — up to 8 or 10 — to distribute the weight and prevent the tail from pulling loose later.

Joining Yarn in Color Patterns and Stripes

For stripes or color blocks where you'll use both colors again, you can carry the unused yarn up the side of your work instead of cutting it. Twist the two yarns around each other at the edge every row or two to keep the edge neat. This saves you from having to weave in many ends.

If you're switching colors and won't use the old color again, cut it and weave in the ends as described above. If you're doing a pattern like Fair Isle where both colors are used in the same row, hold both yarns and weave them together loosely at the back of your work. Weave in the ends after you finish.

Common Mistakes to Avoid

The most common error is tying the old and new yarns together with a knot while you're still knitting. This creates a hard lump that shows on the front of your work and can catch on your needles. Save the knot for after you finish — or better yet, skip the knot entirely and just weave in the ends.

Another mistake is cutting the old yarn too short. A 4-inch tail gives you enough length to thread onto a yarn needle and weave through several stitches. If your tail is only 1 inch long, it's nearly impossible to hide and may work loose. If you accidentally cut it too short, you can tie a small knot at the end and weave that in, though it will create a small bump.

Don't weave in the ends while your project is still on the needles. Wait until you've bound off completely. Weaving in ends too early can distort your stitches and make the join more visible.

Frequently Asked Questions

Can I tie a knot to join yarn while I'm knitting?

You can, but it's not recommended. A knot creates a lump that's visible on the front of your work and can catch on your needles as you knit. It's better to join without a knot and weave in the tails later, which hides the join completely.

What if my yarn tail is too short to thread onto a needle?

Tie a small knot at the very end of the tail to give it weight and make it easier to handle. Thread the knot through the eye of your yarn needle, then weave the tail through the stitches. Trim close to the fabric. The knot will sit inside the weave and won't be visible.

How do I hide a join in the middle of a visible row?

Weave the tails through the backs of stitches on the wrong side of your fabric, spreading the join across 4 to 6 stitches. On smooth stockinette stitch, this join will be nearly invisible from the front. On textured stitches, consider joining at the edge of a row instead, where the join is naturally less noticeable.

Do I have to weave in ends right after I bind off?

No. Many knitters weave in ends after the project is complete and washed. Washing can help even out the tension at the join and make it less noticeable. You can weave in ends when ready or wait — whatever works for your schedule.

What's the best way to join yarn in a stretchy or delicate yarn?

Use a longer weave — 8 to 10 stitches instead of 4 to 6 — to distribute the weight of the tail and prevent it from pulling loose. For very delicate yarns, consider joining at the edge of a row where the join is less stressed. Test the join by gently pulling on it after weaving to make sure it's find.