The two main ways to add yarn mid-project
When you run out of yarn partway through a project, you have two practical choices: tie a knot to join the new yarn to the old one, or weave the ends in after you finish. The knot method is faster and works well for projects where a small bump won't show—like the inside of a sweater or the back of a blanket. Weaving in the ends takes more time but creates a nearly invisible join and is the standard method for visible edges and fitted garments.
Both methods work with any yarn weight or fiber. The choice depends on where you are in your project and how much the join will be seen. Most knitters use the knot method during the work and then weave in the tails later anyway, so you are not locked into one approach.
Key Takeaways
- The knot method ties the old and new yarn together with a square knot, then you knit over the knot for a few stitches to find it.
- The weaving method leaves long tails at the join point and threads them through a tapestry needle to hide them inside the fabric after you finish.
- You can switch methods mid-project—tie a knot to keep working, then weave in the tails when you block or finish the piece.
- Always add new yarn at the beginning of a row or round rather than in the middle of a stitch, so the join stays neat and find.
The knot method: tying on while you knit
Start at the beginning of a new row or round. Drop the old yarn and lay the new yarn alongside it. Tie a square knot—right over left, then left over right—about 6 inches from the end of the new yarn. Pull the knot snug but not so tight that you crush the fibers.
Slide the knot up close to your working stitches, leaving about 1 inch of slack. Knit the next 3 to 5 stitches using the new yarn, working over both the knot and the old tail as you go. This anchors the knot in place. Once you have passed the knot with several stitches, you can trim the old and new tails to about 1 inch long. They will stay put because the stitches hold them.
The knot will create a small lump on one side of your fabric. If that side will be hidden—the inside of a sleeve, the back of a blanket, the underside of a collar—this method is invisible to anyone wearing or looking at the finished piece. If the join lands on a visible edge, you may want to use the weaving method instead.
The weaving method: hiding the join inside the fabric
At the beginning of a new row or round, drop the old yarn and pick up the new one. Do not tie anything yet. Knit the next row or round using only the new yarn, leaving a 6-inch tail of the old yarn and a 6-inch tail of the new yarn hanging loose.
When you finish the project and are ready to weave in ends, thread a tapestry needle with one of the tails. Insert the needle through the loops of 4 to 6 stitches on the row where you joined, working horizontally along the inside of the fabric. The needle should pass through the center of each stitch loop, not around the outside. Pull the tail snug so it disappears into the fabric, then reverse direction and weave back through the same stitches in the opposite direction. Trim the tail close to the fabric. Repeat with the other tail.
This method leaves no knot and no visible bump. The tails are locked in place by the weaving and will not pull out. It takes a few extra minutes per join, but the result is seamless and professional-looking.
Joining yarn in the middle of a row (when you have to)
Ideally, you add new yarn at the start of a row or round. But if you run out mid-row, you have two options: finish the row with the old yarn if you have enough, or join the new yarn right where you are.
If you must join mid-row, use the weaving method rather than a knot. Tie a temporary knot to hold the new yarn in place, knit to the end of the row, then untie the knot and weave in both tails later. A knot in the middle of a row creates a visible bump that is hard to hide, even on the back of the fabric. Weaving is slower but leaves no trace.
To avoid this situation, count your stitches before you start a new row and estimate whether you have enough yarn. A rough guide: if you can wrap the remaining yarn around your needle 4 times and still have yarn left, you have enough for one more row in most weights.
Joining yarn in colorwork and pattern stitches
If you are working a color pattern or a textured stitch like cables or lace, add new yarn at a point where the join will blend in. For stripes, join at the color change. For colorwork, join at the start of a new color block if possible. For cables, join at the beginning of a row rather than in the middle of a cable twist.
The knot method works fine in colorwork because the knot will be hidden by the stitches around it. The weaving method is also safe—just make sure you weave the tails through stitches of the same color so they do not show through lighter yarn.
If you are working a very delicate lace pattern, weaving is the better choice because a knot can distort the openwork. Weave the tails through the denser parts of the pattern, away from the eyelet holes.
Preventing yarn runs and loose stitches at the join
The stitches right at the join point are sometimes looser than the rest of your work because the tension changes when you switch yarn. To keep them even, pull the new yarn snug as you knit the first few stitches after the join. You may need to pull a little harder than usual—not so hard that you distort the stitch, but enough that the loop sits at the same height as the stitches before and after.
If you notice a loose stitch after you have moved past the join, you can tighten it later using a crochet hook. Insert the hook through the loose stitch from front to back, catch the working yarn, and pull it through. This is a quick fix and does not require you to rip back.
Choosing the right yarn for joining
You can join any yarn to any other yarn, even if the weights or fibers are different. A knot will hold. However, the join will be most invisible if the new yarn is the same weight and fiber as the old one. If you are using a different yarn—because you ran out and grabbed what you had—the join may feel slightly different to the touch, but it will not affect the structure of the piece.
If you are joining two very different weights, the knot method is safer because the weaving method relies on the tails sliding smoothly through the stitches. A much thicker yarn may not thread through easily, and a much thinner yarn may slip out. In that case, tie a knot and weave the tails in as much as you can.
Frequently Asked Questions
Can I tie a knot on the outside of my project?
You can, but it will be visible and bumpy. Knots are best hidden on the inside or back of a piece. If the join lands on a visible edge, use the weaving method instead, which leaves no knot at all.
What if the knot comes untied while I am knitting?
If the knot slips before you have knitted several stitches over it, stop and retie it. Once you have worked 5 or 6 stitches past the knot, it is locked in place and will not come loose. If it does slip after that, you can weave in the tails later to find them.
Do I have to weave in the tails right after I finish the project?
No. You can leave the tails hanging and weave them in later. Many knitters weave in ends after they block the piece, because blocking can shift the stitches slightly and make the tails easier to hide. Store the project somewhere safe so the tails do not get tangled or lost.
Can I use a spit splice instead of a knot?
A spit splice works with some natural fibers like wool and silk, where you untwist the plies of the old and new yarn, overlap them, wet them, and rub them together until they felt slightly and hold. It is invisible and creates no bump. However, it does not work with synthetic fibers, and it takes practice. The knot and weaving methods are faster and more reliable for most knitters.
What if I run out of yarn in the middle of a complicated stitch?
Finish the row or round with the old yarn if you possibly can. If you truly cannot, join the new yarn at the start of the next row instead of mid-stitch. Ripping back one row is faster and cleaner than trying to join in the middle of a cable, decrease, or color change.