The two main ways to change yarn colours
You change colours in knitting by either cutting the old yarn and tying on the new one, or carrying the unused colour inside your stitches until you need it again. Which method you use depends on how far apart your colour changes are and whether you want visible joins or hidden floats on the back of your work.
The cut-and-tie method works best when you are switching colours for a large section — say, knitting ten rows in blue, then ten rows in red. The carrying method (called stranding) works best when colours alternate frequently, like in a Fair Isle pattern where you switch back and forth every few stitches.
Most knitters use both methods in the same project. A striped blanket might use cut-and-tie at each stripe boundary. A patterned sweater might use stranding for the patterned section and cut-and-tie for solid-colour sections above and below it.
Key Takeaways
- Cut the old yarn and tie the new yarn on with a square knot when you are finished with a colour for good, or when colour blocks are large enough that carrying yarn would create bulky floats.
- Strand (carry) the unused colour inside your stitches when you switch back and forth between two colours within the same row or within a few rows of each other.
- Tension on carried yarn matters: if it is too tight, your fabric will pucker; if it is too loose, you will have loops on the back that catch fingers.
- Weave carried yarn into your stitches every few stitches to prevent long floats that can snag, especially on garments that will be worn.
- Practice the method on a small swatch before starting a project so the colour changes look even and your tension stays consistent.
Cutting and tying on new yarn
Cut the old yarn, leaving a tail about 4 to 6 inches long. Leave the same length of tail on the new yarn. Tie the two tails together using a square knot — right over left, then left over right — pulled snug but not so tight it distorts the stitch.
Position the knot so it sits on the wrong side of your work (the side that faces inward when you wear the garment). If you are working flat, this is the back. If you are working in the round, tie the knot on the inside.
After you finish knitting, you will weave these tails into the back of your work using a tapestry needle. This is called weaving in ends. Thread the tail through the needle, then run it through the loops of several stitches on the wrong side, changing direction halfway through so the tail does not unravel. Trim any excess.
This method leaves a clean join on the right side of your work. Use it whenever you are done with a colour permanently, or when you are switching between large blocks of colour (usually more than five or six rows).
Stranding: carrying yarn inside your stitches
Stranding means you keep both colours attached and carry the unused one along the inside of your row, catching it into your stitches as you go. Start by tying both yarns together at the beginning of the row where the colour change happens.
Knit with the first colour for as many stitches as the pattern calls for. When you reach the point where you need to switch, drop the old colour and pick up the new one. The old colour now sits on the wrong side of your work, waiting to be used again.
Every few stitches — usually every two to four stitches, depending on how loose your tension is — catch the carried yarn by knitting it into a stitch. To do this, lay the carried yarn over your left needle before you knit the next stitch, then knit normally. The new stitch will trap the carried yarn on the wrong side.
The goal is to space these catches evenly so the carried yarn does not create visible bumps on the right side, and so it does not form long loops on the wrong side that can snag. If you are unsure how often to catch, practice on a swatch first.
Tension when carrying yarn
The most common mistake with stranding is pulling the carried yarn too tight. When you pick up the carried colour, do not yank it. Let it sit loosely on your needle so the stitches you are making stay the same size as the stitches around them.
If carried yarn is too tight, your fabric will pucker and the stitches will look smaller in that area. If it is too loose, you will see loops on the wrong side that stick out and can catch on things when the garment is worn.
The carried yarn should sit snugly inside your stitches, but not so snugly that it distorts them. This takes practice. Knit a few rows of a two-colour pattern on a swatch and look at both sides. The right side should be smooth. The wrong side should show the carried yarn woven neatly through the stitches, with no visible loops or puckers.
Weaving in carried yarn as you go
Instead of catching carried yarn every few stitches by hand, some knitters use a technique called weaving in. As you knit, you trap the carried yarn under or over the working yarn at regular intervals, so it becomes part of the fabric rather than just sitting on top of it.
To weave in on a knit stitch: lay the carried yarn over your left needle, insert your right needle into the stitch, bring the working yarn under the carried yarn, and knit normally. The carried yarn is now trapped under the new stitch.
To weave in on a purl stitch: lay the carried yarn under your left needle, insert your right needle into the stitch, bring the working yarn over the carried yarn, and purl normally. The carried yarn is now trapped over the new stitch.
Alternate which direction you weave (under on knit rows, over on purl rows, or vice versa) so the carried yarn does not create a visible line on the right side. This method takes more attention than straightforward catching, but it distributes the carried yarn more evenly and prevents long floats.
Switching colours in the middle of a row
When you need to change colours mid-row (as in Fair Isle or jacquard patterns), drop the old colour where you are and pick up the new colour. Twist the two yarns around each other once before you knit the next stitch. This twist closes the gap between the two colours so you do not end up with a hole in your fabric.
The twist should happen on the wrong side of your work. If you are working flat, twist below your needles. If you are working in the round, twist on the inside of the circle.
After you twist, knit with the new colour until you need to switch back. When you do, twist again. This prevents gaps and keeps your colour changes looking neat.
Joining a new colour at the edge of your work
If you are changing colours at the start of a new row (like in stripes), tie the new yarn on at the edge stitch, leaving tails on both sides. Knit the first stitch normally with the new colour. The edge stitch will hide the join.
This is cleaner than tying on in the middle of a row, because edge stitches are easier to weave in later and the join is less visible. Always plan colour changes to happen at row edges when you can.
Frequently Asked Questions
How do I know if I should cut the yarn or strand it?
Cut and tie on if you are finished with a colour, or if the colour block is large (more than five or six rows). Strand if you are switching back and forth between colours within the same row or within a few rows of each other. If you strand over a large block, the floats on the back will be too long and will snag.
What happens if my carried yarn is too loose?
Loose carried yarn creates loops on the wrong side that stick out and catch on things when the garment is worn. It also makes the stitches look uneven. Catch the carried yarn more often, or catch it more snugly, and practice on a swatch until the tension feels right.
Can I use more than two colours at once?
Yes, but it becomes harder to manage. Stranding three colours means two colours are being carried at all times, which makes tension control difficult and creates thick floats. Most knitters limit stranding to two colours and use cut-and-tie for a third colour, or break the work into separate sections.
Do I have to weave in ends after I tie on new yarn?
Yes. Tails left unknotted will unravel, and knots can come undone in the wash. Thread each tail through a tapestry needle and run it through the loops of several stitches on the wrong side, changing direction halfway through. This anchors the tail so it cannot slip out.
What is the difference between stranding and intarsia?
Stranding carries unused yarn inside your stitches and works best for small, repeating patterns. Intarsia uses separate bobbins of yarn for each colour block and works best for large, non-repeating designs (like a picture knit into a sweater). Intarsia prevents long floats but requires more setup and attention.