What a Slip Stitch Is and Why You Use It

A slip stitch is a hand-sewn stitch that closes an opening from the inside, leaving almost no visible thread on the outside. The needle travels inside the fold of fabric on one side, then slips through a few threads of the opposite fold, then back inside the first fold. Because the thread runs hidden inside the fabric layers, the seam looks closed but not stitched—which is why it's also called an invisible stitch.

You use a slip stitch to close openings after you've stuffed a pillow, turned a garment right-side out, or sewn a patch onto fabric. It's the standard finish for closing the gap you leave when turning a pillowcase or stuffed animal, because machine stitching that seam would show on the outside. A slip stitch is also stronger than it looks—the thread anchors into both layers of fabric, so it holds well even under stress.

Key Takeaways

  • A slip stitch hides the thread inside the fold of fabric, so the seam looks closed without visible stitching on the outside.
  • You thread the needle through the fold of one piece of fabric, then catch just a few threads from the opposite fold, then back into the first fold—repeating this pattern along the opening.
  • The stitch works best on seams where both sides are folded under or where you're closing a gap between two folded edges.
  • Practice on scrap fabric first; the stitch takes patience but becomes faster once your hand learns the rhythm.

Setting Up Your Thread and Needle

Use thread that matches the fabric color as closely as possible. If you can't find an exact match, choose a shade slightly darker rather than lighter—it's less visible. Cut a length of thread about 18 to 24 inches long; longer threads tangle and fray, shorter ones mean you'll have to tie on a new thread more often.

Thread a needle with a size appropriate to your fabric—a size 7 or 8 for most cottons and blends, smaller for delicate fabrics. Tie a small knot at the end of the thread. You'll hide this knot inside the fabric, so it won't show on the finished seam.

The Basic Slip Stitch Motion

Start by inserting your needle into the fold of fabric on one side of the opening, about a quarter-inch from where you want to begin stitching. Push the needle through the fold so it travels inside the fabric for about half an inch, then bring it back out through the fold. This hides your starting knot inside the fold.

Now make your first stitch: insert the needle directly across from where it just came out, into the fold of the opposite piece of fabric. Travel inside that fold for about half an inch, then bring the needle back out. From that exit point, catch just 2 or 3 threads from the first piece of fabric—don't go all the way through to the outside. Then insert the needle back into the fold of the first piece, directly across from where you just caught those threads.

Repeat this pattern: travel inside one fold, come out, catch a few threads from the opposite side, go back into the first fold. Keep your stitches small and even—about a quarter-inch apart along the seam. The smaller and closer your stitches, the stronger and less visible the seam will be.

Keeping the Seam Invisible

The key to an invisible stitch is catching only a few threads from the opposite fabric, not going all the way through to the outside. If your thread shows on the outside, you're catching too many threads or pulling too tight. Loosen your tension slightly and make sure you're catching just the surface threads of the fold.

Pull the thread snug after every 3 or 4 stitches, but not so tight that you pucker the fabric. The thread should disappear into the fold without creating dimples or bunching. If you see puckering, loosen your next few stitches slightly.

As you work, the two folded edges should come together naturally and close the opening. If there's a gap between the folds, your stitches are too loose. If the fabric is puckering, they're too tight. Adjust as you go.

Closing Off Your Thread Securely

When you reach the end of the opening, make one final stitch inside the fold to hide your thread. Bring the needle out through the fold, then insert it back in right next to where it came out and travel inside the fold for about half an inch. Bring the needle back out and trim the thread close to the fabric. The thread will slip back inside the fold and disappear.

Alternatively, tie a small knot inside the fold by wrapping the thread around your needle once and pulling it tight, then insert the needle back into the fold and travel inside it before bringing the needle out and trimming. Either method hides the knot inside the fabric so it won't show.

Common Mistakes and How to Avoid Them

The most common mistake is pulling the thread too tight, which puckers the fabric and makes the seam visible. Pull just snug enough that the opening closes; the fabric should lie flat. Another mistake is catching too many threads from the opposite fold, which makes the stitch visible on the outside. Catch only 2 or 3 surface threads, not a whole layer.

If your thread keeps breaking, you may be pulling too hard or using a thread that's too thin for your fabric. Use a thread weight matched to your fabric weight, and pull with steady, even pressure rather than jerking. If you're having trouble seeing where to insert the needle, work in good light and use a needle threader if your eyesight needs help.

Slip Stitch on Different Fabric Types

On lightweight fabrics like cotton voile or linen, use a smaller needle and shorter stitches—about an eighth of an inch apart. The fabric is delicate, so small stitches distribute the stress and prevent tearing. On heavier fabrics like canvas or upholstery cotton, you can use slightly longer stitches, about a quarter-inch apart, because the fabric is stronger.

On stretchy fabrics like knits or jersey, use a ballpoint needle instead of a sharp needle; it slides between fibers rather than piercing them, which prevents runs. Keep your stitches small and your tension moderate so the seam doesn't pucker when the fabric stretches.

Frequently Asked Questions

Can I use a slip stitch on a seam that's not folded under?

A slip stitch works best when both edges are folded under or when you're closing a gap between two folded edges. If the raw edges are exposed, the stitch won't hide the thread. Fold the raw edges under first, press them flat, and then slip stitch them closed.

How do I know if my slip stitch is strong enough?

A slip stitch is strong when your stitches are small, close together, and you're catching threads from both layers of fabric. Test it by gently pulling on the seam; it should hold without the thread sliding through the fabric. If it feels loose, your stitches are too far apart or too loose—go back and add more stitches or tighten them slightly.

What if I can still see the thread on the outside?

You're likely catching too many threads from the opposite fold or pulling too tight. Catch only 2 or 3 surface threads, not a whole layer. Also check that your thread color matches the fabric; even a small mismatch becomes visible. If the thread is still showing, you may need to remove those stitches and start over with better tension.

Can I use a slip stitch on curved seams?

Yes, but keep your stitches smaller on curves—about an eighth of an inch apart—so the seam follows the curve smoothly without puckering. On tight curves, you may need to ease the fabric slightly as you stitch to keep it from bunching.

How long does a slip stitch take to learn?

Most people can make a functional slip stitch after practicing on scrap fabric for 10 to 15 minutes. It becomes faster and neater with practice—after closing 3 or 4 projects, your hand learns the rhythm and you'll work much more quickly. Don't rush; a slow, careful stitch is better than a fast, sloppy one.