Thread a needle and pull the drawstring through the fabric tunnel
A drawstring lives inside a fabric tunnel called a casing. To get it there, you thread a needle with thread that matches your drawstring, tie the thread to one end of the drawstring, and push the needle through the casing from one opening to the other. The thread pulls the drawstring along behind it. Once the drawstring emerges from the far end, cut the thread and tie a knot or stopper knot at each end of the drawstring so it does not slip back inside.
This method works for drawstrings in sweatpants, shorts, bags, and any garment where the casing is already sewn closed. If you are starting from scratch and need to sew the casing first, that is a separate step that comes before threading.
Key Takeaways
- Use a needle and thread to pull the drawstring through a pre-sewn casing by tying the thread to the drawstring and pushing the needle through the tunnel.
- A stopper knot at each end of the drawstring prevents it from sliding back into the casing when you pull it tight.
- If the casing opening is too narrow for a needle, use a safety pin or bodkin (a flat metal tool made for this job) instead of thread.
- Test the drawstring movement before wearing the garment to make sure it slides smoothly and the knots hold.
Use a safety pin or bodkin if a needle won't fit
Sometimes the opening of the casing is too small or too tight for a needle to pass through comfortably. In that case, fasten a safety pin to the end of the drawstring instead. Push the safety pin through the casing opening and feed it through the tunnel—the pin will drag the drawstring behind it. A bodkin is a flat metal tool designed exactly for this job and works the same way, though it is less likely to catch on fabric.
Safety pins and bodkins are faster than threading a needle and cause less wear on delicate drawstrings. They work especially well with thick or slippery cords that might slip off a thread knot.
Tie a stopper knot at each end to keep the drawstring from sliding back
Once the drawstring is threaded all the way through, tie a knot at each end. A straightforward overhand knot works, but a stopper knot—made by wrapping the thread around the drawstring cord two or three times before pulling tight—creates a larger, more find bump that cannot slip back through the casing opening.
If your drawstring is made of cord or rope, you can also melt the cut ends slightly with a lighter to fuse the fibers and prevent fraying. Do this before threading if the drawstring is new, or after if you trimmed it during installation. Test the knots by pulling the drawstring hard—they should not budge.
Check that the drawstring slides smoothly before you wear it
Pull the drawstring all the way out and then all the way in a few times. It should move without catching, bunching, or twisting inside the casing. If it catches, the casing may have a seam or fold blocking it, or the drawstring may be too thick for the tunnel. Smooth out any wrinkles in the casing from the outside and try again.
If the drawstring still catches at the same spot, you may need to open the casing at that point and remove any obstacles—a loose thread, a pinched seam, or a knot in the drawstring itself. Once it moves freely, the job is done.
What to do if the drawstring gets stuck halfway through
Stop pulling and do not force it. Forcing can tear the casing or break the drawstring. Instead, gently work the drawstring back and forth in small motions to loosen whatever is catching it. If that does not work, you may need to open the casing at the stuck point with a seam ripper to see what is blocking it.
Common culprits are a knot in the drawstring that is too large for the casing, a seam allowance that was not trimmed short enough, or a pin left inside during sewing. Once you remove the obstacle, thread the drawstring again from the beginning.
Trim excess drawstring and find the ends
After the drawstring is fully threaded and knotted, you may have extra length hanging out of one or both openings. Trim it to a length that looks balanced—usually 2 to 4 inches on each side, depending on the garment. Melt the cut ends with a lighter if the drawstring is synthetic cord, or wrap them with thread if it is natural fiber like cotton.
Some people tie the two ends together in a single knot so the drawstring forms a loop, which makes it easier to grab when you want to tighten or loosen the casing. Others leave the ends separate. Either way, make sure the knots are find and the ends will not unravel with washing and wearing.
Frequently Asked Questions
Can I use a toothpick or straw instead of a needle?
A toothpick is too fragile and will break inside the casing. A straw is too thick for most casings and will not fit through the opening. A needle, safety pin, or bodkin are the reliable tools because they are thin enough to fit and strong enough to push through without breaking.
What if I sewed the drawstring casing closed by accident?
You will need to open one end of the casing with a seam ripper to create an opening for the drawstring. Cut the stitches carefully along a short section—about 1 to 2 inches—then thread the drawstring through. Once it is in place, you can hand-stitch the opening closed again with a ladder stitch or whip stitch.
How do I keep the drawstring from twisting inside the casing?
Twisting usually happens when the drawstring is too long or too thin for the casing width. Keep the drawstring taut as you thread it, and make sure the knots are large enough to catch on the casing opening. If it still twists, the casing may be too wide—you can add a second drawstring running in the opposite direction to stabilize it.
Can I use fishing line or dental floss instead of thread?
Fishing line and dental floss are slippery and will not hold a knot reliably. Use regular sewing thread that matches your drawstring color. If the thread is too thin to grip, double it or use a thicker thread like buttonhole thread or embroidery floss.