The three main ways to join a new color
You join colors in knitting by carrying the old yarn along the edge of your work, weaving a new color in as you knit, or tying the yarns together and hiding the knot inside your stitches. The method you choose depends on whether you are switching colors once or many times, how visible your edges will be, and how much bulk you can tolerate inside your fabric.
Each technique has a real trade-off. Carrying yarn along the edge is fast and keeps your edges neat, but only works for small gaps between color changes. Weaving in a new color as you go takes longer but gives you control over where the old yarn sits. Tying and burying a knot is the simplest to learn and works for any gap size, but creates a small lump that shows if your fabric is thin or light-colored.
Key Takeaways
- Carrying the old yarn up the edge works best when you switch colors every few rows, because loose strands longer than half an inch will snag.
- Weaving the old yarn into new stitches as you knit hides it inside the fabric and works for any color-change distance, but requires attention to tension.
- Tying the two yarns together with a square knot and burying the knot inside your work is the easiest method to learn and works for large gaps between colors.
- Duplicate stitch, worked after knitting is done, lets you add small areas of color without joining yarn at all, though it is slower than knitting in the color.
Carrying yarn up the edge for frequent color changes
When you switch colors every few rows—say, in a striped pattern—you can carry the unused yarn up the side of your work instead of cutting it. Hold the old yarn loosely along the edge as you knit the first stitch of the new color, then knit normally. The old yarn will sit inside the edge stitch and stay hidden.
This method is fast and keeps your edges clean, but only works if the gap between color changes is small. A loose strand longer than half an inch will catch on things and pull your edge out of shape. If you are switching colors more than four rows apart, use a different method.
To carry yarn up the edge: knit the first stitch of your new color with the old yarn held against the needle. The new stitch will trap the old yarn inside. Continue knitting with the new color. When you switch back, repeat the process with the new color held along the edge.
Weaving yarn in as you knit for medium gaps
Weaving lets you hide the old yarn inside your new stitches without cutting it, and it works for color changes that are several rows apart. As you knit with the new color, you hold the old yarn loosely across your working yarn and knit over it every other stitch or every third stitch, depending on how much of the old yarn you need to find.
The key is keeping the old yarn loose enough that it does not pucker your stitches. If you pull too tight, your fabric will bunch. If you leave it too loose, it will create loops on the inside that can snag. Most knitters learn this by feel after a few tries.
To weave: hold the old yarn in your left hand (or right, depending on your style) and lay it across your working yarn before you insert the needle into the next stitch. Knit the stitch normally—the working yarn will trap the old yarn underneath. On the next stitch, lay the old yarn on top of the working yarn before you knit. This over-under pattern hides the old yarn evenly inside the fabric.
Tying and burying a knot for any color gap
The simplest method is to tie the old yarn and new yarn together with a square knot, then hide the knot inside your work. This works for any distance between color changes and requires no special technique beyond tying a basic knot.
Tie a square knot by crossing the old yarn over the new yarn, wrapping around and pulling tight, then crossing the new yarn over the old yarn and wrapping around again. The knot should sit close to your needles. Knit the first stitch with both yarns held together, then drop the old yarn and continue with the new yarn alone. On the next row, the knot will sit inside the fabric where it will not show.
The trade-off is a small lump where the knot sits. In thick, textured yarn this is invisible. In thin or light-colored yarn, you may see a bump. If that matters for your project, use weaving instead.
Duplicate stitch for adding color after knitting
Duplicate stitch is a way to add color to finished knitting by embroidering over existing stitches with a threaded needle. You do not join yarn at all—you straightforward thread new yarn through a needle and follow the path of the stitch you want to cover.
This method is useful for small areas of color, like adding a motif or fixing a color mistake. It is slower than knitting the color in, because you work one stitch at a time after the piece is done. But it means you can add color without planning ahead or managing multiple yarns while you knit.
To duplicate stitch: thread a needle with the new color and bring it up through the base of the stitch you want to cover. Follow the path of the original stitch—up and over the stitch above it, then back down through the base. The new yarn will sit on top of the old stitch and look like it was knitted in that color.
Avoiding loose edges and puckering
The most common mistake when joining colors is leaving the first stitch of the new color too loose. When you switch colors, that first stitch is the hardest to tension correctly because you are holding two yarns. Pull the new yarn snug as you knit the first stitch, or the edge will look sloppy.
If you are weaving yarn in, the second most common mistake is pulling the old yarn too tight. This bunches your stitches and distorts the fabric. Weave loosely and check your work as you go. If a stitch looks tight, you pulled too hard on the old yarn.
If you are carrying yarn up the edge, make sure the carried yarn is not so tight that it pulls your edge inward. The edge should lie flat and straight, not curved or gathered.
Choosing a method for your project
Stripes every few rows: carry yarn up the edge. It is the fastest and keeps edges neat.
Color changes several rows apart: weave the old yarn in as you knit. It hides yarn inside the fabric and works for any gap size.
Large gaps or one-time color changes: tie the yarns together and bury the knot. It is straightforward and works for any distance.
Small motifs or fixes: duplicate stitch after knitting. It lets you add color without managing multiple yarns.
If you are unsure which method will work best, knit a small swatch with your yarn and try all three. You will quickly see which one feels natural and produces the look you want.
Frequently Asked Questions
Can I cut the old yarn and weave in the ends later instead of joining?
Yes, you can cut the yarn and weave in the ends with a tapestry needle after knitting is done. This works for any color change. The trade-off is extra finishing work—you will have two ends to hide for every color change. If you have many color changes, carrying or weaving as you go is faster overall.
What if my knot shows through the fabric?
If the knot is visible, your yarn is too thin or your fabric too tight to hide it. Try weaving the old yarn in instead, or use a smaller knot by tying with just the ends of the yarn rather than the full strands. For future projects, consider whether the knot matters—in many textured pieces, it will not show at all.
How do I keep my edges from looking messy when I switch colors?
Pull the first stitch of the new color snug. This is the stitch that anchors the color change and sets the tension for the edge. If that stitch is loose, the whole edge will look loose. Practice on a swatch until you find the right tension.
Can I use all three methods in the same project?
Yes. Use whichever method works best for each color change. Stripes can use carried yarn, a large motif can use a tied knot, and small details can use duplicate stitch. Most knitters mix methods depending on what the pattern needs.