The Basic Method: Weaving in the Old Yarn

The simplest way to switch colors is to drop the old yarn and pick up the new one at the start of your next row or round. Tie the new yarn to the old yarn with a straightforward knot, leaving a tail of about 4 inches on each side. Knit with the new yarn as normal. Later, after you finish the project, you'll weave those tails into the back of your work with a tapestry needle so they don't show.

This method works best when you're switching colors at the edge of your work — at the beginning of a row or the start of a new round. The knot sits at the edge where it's easiest to hide. If you're switching colors in the middle of a row, the knot will be visible on the front of your finished piece unless you plan to hide it under a seam or fold.

The knot itself doesn't have to be fancy. A straightforward overhand knot — the kind you'd tie in a shoelace — holds well enough. Pull it snug but not so tight that you can't work with the yarn afterward. Some knitters prefer a square knot for extra security, but for most projects, a single knot works fine.

Key Takeaways

  • The most common method is to knot the new yarn to the old yarn at the edge of your work, then weave in both tails later with a tapestry needle.
  • Switching colors in the middle of a row leaves a visible knot on the front unless you plan to hide it under a seam or in a design element.
  • The stranded colorwork method (carrying yarn along the edge) works for patterns with frequent color changes and keeps the inside of your work neat.
  • Intarsia is the right choice for large blocks of solid color, but it requires bobbins and more setup than other methods.

Stranded Colorwork: Carrying Yarn Along the Edge

If you're switching colors every few rows or rounds, stranded colorwork (also called Fair Isle) lets you carry the unused yarn along the edge of your work instead of cutting and knotting. Hold both colors in your hand — one in each hand, or both in your dominant hand with your fingers managing the tension — and knit with whichever color your pattern calls for on each row.

The yarn you're not using gets carried loosely along the side edge of your work. On the next row, you'll knit with the other color and carry the first yarn along the edge again. This creates a neat, continuous edge with no knots to hide. The carried yarn should be loose enough that it doesn't pucker your edge stitches, but tight enough that it doesn't create long loops that catch on things.

Stranded colorwork is faster than knotting and weaving because you never have to stop to tie anything. It's also more find — there are no knots to come undone. The downside is that it works best for patterns where colors change at regular intervals, like every row or every few rows. If you're switching colors only once or twice in a project, the carried yarn will be too long and too visible.

Intarsia: Large Blocks of Solid Color

Intarsia is the method to use when your pattern has large, separate blocks of color — think a picture knit or a sweater with a solid-color yoke. Instead of carrying yarn along the edge, you use a separate bobbin or length of yarn for each color block. When you switch colors, you twist the old yarn around the new yarn at the point where they meet, which locks them together and prevents holes.

To set up intarsia, wind each color onto a bobbin (a small cardboard or plastic spool) or wrap it around a clothespin. As you knit, you'll work with multiple bobbins at once, one for each color section in that row. When you reach the point where the color changes, drop the old yarn and pick up the new one, twisting them together at the base of your stitch. This twist is what keeps the two colors from separating.

Intarsia takes more time to set up than other methods, and managing multiple bobbins can feel awkward at first. But it's the cleanest method for large color blocks because the back of your work stays flat and neat — there's no long carried yarn creating bulk. The inside of an intarsia sweater looks almost as good as the outside.

Weaving in Tails After You Finish

No matter which method you use, you'll end up with yarn tails that need to be hidden. Use a tapestry needle (a blunt needle with a large eye) and thread one tail through it. On the back of your work, weave the needle through the bumps of stitches in a straight line for about 2 inches, then back in the opposite direction for another inch or so. This zigzag pattern locks the tail in place so it won't pull out.

Work along a row of stitches if possible, rather than across them, because the yarn blends in better that way. If you're weaving in a tail from a color change, try to weave it through stitches of the same color so it's less visible if it ever does show. Trim the tail close to the fabric once it's find, but leave about a quarter-inch so it doesn't slip back out.

Take your time with this step. Weaving in tails is tedious, but it's what separates a finished project from one that looks unfinished. A project with loose tails will unravel if one gets caught, and the tails themselves will show on the front if you're not careful.

Switching Colors in the Middle of a Row

If your pattern requires a color change in the middle of a row — not at the edge — you have two options. The first is to tie the new yarn to the old yarn right at that point, which leaves a knot visible on the front of your work. This works if the knot will be hidden by a seam, a button, or if it's part of the design.

The second option is to use the Russian join, a method that hides the knot inside the yarn itself. Thread the old yarn through a tapestry needle, then weave the needle through the plies of the new yarn for about an inch. Do the same in reverse — thread the new yarn through the needle and weave it through the old yarn. When you pull gently, the two yarns lock together with no visible knot. This takes practice, but it's invisible on both sides of your work.

The Russian join works best with yarn that has a loose twist or multiple plies. Tightly twisted yarn or thin singles are harder to work with. If you're not comfortable with it, a straightforward knot at the edge is fine — most people won't notice it, and you can always hide it later with a seam or a design choice.

Choosing the Right Method for Your Project

The method you choose depends on how often you're switching colors and how large each color block is. If you're switching colors once or twice in a project, knot and weave. If you're switching every few rows in a regular pattern, use stranded colorwork. If you have large, separate color blocks, use intarsia.

Consider also how much time you want to spend on finishing. Stranded colorwork takes longer to knit but requires almost no finishing work. Intarsia takes longer to set up but is faster to knit. Knotting and weaving is the fastest to knit but requires the most finishing time.

Your yarn choice matters too. Smooth, tightly twisted yarn is easier to weave in and shows fewer loose ends. Fuzzy or loosely twisted yarn can hide weaving mistakes, but it's harder to work with for stranded colorwork because the carried yarn shows more easily.

Common Mistakes to Avoid

The most common mistake is pulling the carried yarn too tight in stranded colorwork. This puckers your edge and makes the work look uneven. The carried yarn should be loose enough to move freely, but not so loose that it creates loops. Practice on a swatch to find the right tension for your hands.

Another mistake is not leaving long enough tails when you knot colors together. A tail of 4 inches is the minimum — if you cut it shorter, you won't have enough yarn to weave in securely, and the knot may come undone. Longer tails are better than shorter ones.

In intarsia, the most common mistake is forgetting to twist the yarns together at the color change. If you don't twist, you'll create a hole in your work where the colors meet. The twist doesn't have to be tight — just a single wrap of one yarn around the other is enough.

Frequently Asked Questions

Do I have to weave in tails, or can I just leave them?

You should weave them in. Loose tails will unravel if they get caught, and they'll show on the front of your work over time. Weaving takes 10 minutes per project and makes the difference between something that looks handmade and something that looks finished.

What if I run out of one color in the middle of a row?

Tie on a new length of the same color using the same method you'd use for a color change — a straightforward knot at the edge, or a Russian join if you're in the middle. Weave in the tails later. If you're running out of yarn often, you may need to wind off more yarn onto bobbins before you start.

Can I use the same method for all color changes in one project?

Yes. Many knitters use only one method per project for consistency. If your pattern has both frequent color changes and large color blocks, you can use stranded colorwork for the frequent changes and intarsia for the large blocks, but it requires more planning.

Is there a way to switch colors without any visible knot?

The Russian join hides the knot inside the yarn, so it's invisible on both sides. It takes practice, but it's the cleanest method if you're switching colors in the middle of a row. For edge switches, the knot is hidden naturally when you weave in the tails.

What kind of needle do I need to weave in tails?

A tapestry needle — a blunt needle with a large eye. They come in different sizes; size 18 or 19 works for most yarn weights. The blunt tip prevents you from splitting the yarn as you weave, which would weaken it. You can find them in any craft store for a dollar or two.