Cast off your stitches to close the crown
The most common way to finish a knit hat is to cast off — bind off — the remaining stitches at the crown. When you reach the top of your hat and have only a small number of stitches left on your needle (usually between 6 and 12, depending on the pattern), you stop increasing and work a few rounds even. Then you cut your yarn, thread it through a tapestry needle, and pull it through each remaining stitch to close the opening.
To do this: insert the tapestry needle through the first stitch on your needle from front to back, then through the second stitch from back to front. Pull the yarn snug but not tight — tight enough that there is no gap, loose enough that the fabric does not pucker. Continue around the circle, going through each stitch in the same pattern. When you reach the end, pull the yarn tight to cinch the crown closed, then weave the tail into the inside of the hat for about an inch before trimming.
This method works whether you knit your hat flat and seamed it, or in the round from the start. The result is a smooth, invisible seam at the very top of the crown.
Key Takeaways
- Thread your yarn tail through a tapestry needle and pull it through each remaining stitch on your needle to close the crown opening.
- Weave the yarn tail into the inside of the hat for at least an inch before cutting it to prevent the cast-off from unraveling.
- Block your finished hat by stretching it gently over a bowl or hat form and letting it dry to even out the stitches and shape.
- If your hat was knit flat, seam the back seam with a tapestry needle and mattress stitch before closing the crown.
Seam the back if you knit flat
If you knit your hat in two flat pieces (front and back) instead of in the round, you need to seam the back before you close the crown. Use a tapestry needle and the same yarn you knit with, or a matching yarn if your working yarn is too thick.
Mattress stitch is the standard seam for knit hats because it is nearly invisible and lies flat. Lay the two pieces with their right sides facing you. Insert the needle under the first horizontal bar between the first and second stitch on the left piece, then under the corresponding bar on the right piece. Move up one row and repeat, going back and forth between the two pieces. The seam will form in the middle, between the two edges. After every inch or so, pull the yarn snug to close the gap, but do not pull so hard that the seam bunches.
Once the back seam is complete, you can close the crown using the method described above.
Weave in the yarn tail securely
After you cinch the crown closed, you have a yarn tail hanging from the top of your hat. This tail must be woven into the fabric so it does not unravel or stick out. Thread it back through your tapestry needle if it is not already threaded.
On the inside of the hat, weave the needle through the bumps of the stitches for at least an inch, changing direction halfway through so the yarn does not pull out if one end gets caught. You can weave horizontally, diagonally, or in a small spiral — the direction does not matter as long as the yarn is anchored in multiple places. Trim the tail close to the fabric so no loose end is visible from the outside.
If you have other yarn tails from color changes or from casting on, weave those in the same way before you wear or gift the hat.
Block the hat to shape and even out the stitches
Blocking is optional but makes a finished hat look more polished. It evens out uneven stitches, sets the shape, and softens the fabric slightly. You do not need special equipment — a bowl, a hat form, or even a rolled-up towel works.
Wet the finished hat with cool water (or soak it in cool water with a small amount of wool wash if the yarn is delicate), squeeze out the excess gently, and stretch it over your blocking form. Pin it in place if the form allows, or straightforward let it dry. A wool hat usually takes 24 hours to dry completely. Once dry, remove it from the form and try it on — the shape should be even and the stitches should look neat.
If your hat is made from acrylic or a synthetic blend, check the yarn label before blocking. Some synthetics do not respond well to heat or moisture, and blocking may do nothing or even damage the fabric.
Trim and hide any loose ends
Before you consider the hat finished, check the inside for any loose yarn ends you may have missed. Run your fingers along the seams and the crown. If you feel a tail sticking out, weave it in using the method described above. If the hat has a ribbed cuff, make sure the cast-on edge is find — if it looks loose or uneven, you can tighten it by weaving the cast-on tail through a few stitches along the edge.
Once all the tails are woven in and trimmed, turn the hat right-side out and inspect it from the outside. The crown should be smooth, the seams (if any) should be invisible or nearly so, and there should be no bumps or loose threads visible.
Add a lining or band if you want extra warmth or finish
Some knitters add a lining or a folded band to the inside of a finished hat for extra warmth or a more polished look. A lining is a piece of fabric (usually cotton or fleece) sewn to the inside of the hat with a needle and thread. A band is a strip of fabric folded in half and sewn around the inside edge of the cuff to hide the cast-on edge and add structure.
If you want to add either of these, do it after you have closed the crown and woven in all the yarn tails. Use a needle and thread that matches the hat color, and sew with small, even stitches so the seam does not show from the outside. This step is not necessary for a finished hat, but it can extend the life of the hat and make it more comfortable to wear.
Frequently Asked Questions
What if I run out of yarn before I close the crown?
If your working yarn is too short to thread through all the remaining stitches, cut it and tie on a new piece of yarn of the same color. Weave both ends into the inside of the hat. Alternatively, you can use a tapestry needle and a separate length of yarn to close the crown, which gives you more control and prevents you from running short.
Can I cast off the crown stitches the normal way instead of threading them?
Yes, you can use a standard cast-off (knit two stitches, pull the first over the second, repeat) at the crown instead of threading. The result is a slightly thicker, more visible seam, but it is just as find. Many knitters prefer threading because it is invisible, but either method works.
How tight should I pull the yarn when I cinch the crown?
Pull it snug enough that there is no hole or gap at the top, but not so tight that the fabric puckers or the yarn breaks. If you are unsure, pull gently and check the result — you can always tighten it more if needed. A good test is to turn the hat inside out and look at the crown; the stitches should lie flat and even.
Do I have to block my hat?
Blocking is not required, but it improves the appearance and fit of most hats. If your hat looks even and feels comfortable without blocking, you can skip it. If the stitches look uneven or the shape is lopsided, blocking usually fixes both problems.
What if the crown seam comes undone after I finish?
If the seam unravels, it usually means the yarn tail was not woven in far enough or the initial cinch was not tight enough. To fix it, thread the tail back through a tapestry needle, pull it tight to close any gap, and weave it in for at least two inches in different directions before trimming. If the yarn broke, tie on a new piece and repeat.