What a slip stitch is and why you need it

A slip stitch is a hand-sewn stitch that closes an opening from the inside, leaving almost no visible thread on the outside. You use it to close the opening after you stuff a pillow, seal a hem that you've folded up by hand, or finish the edges of appliqué work. The thread runs inside the fold of the fabric on both sides, so from the front it looks like the seam was never there.

The slip stitch is different from a running stitch or backstitch because the needle travels hidden inside the fold of fabric rather than across the surface. This makes it the standard choice whenever you want a seam that won't show—which is almost every time you're closing something by hand rather than machine.

Key Takeaways

  • Thread your needle and knot the end, then hide the knot inside the fold of fabric by pushing the needle through the fold and out at the opening.
  • Bring the needle across the opening and insert it directly opposite, then slide it inside the fold of the other side for about a quarter inch before bringing it back out.
  • Repeat this pattern—across the opening, in through one fold, slide inside, out through the fold, across to the other side—keeping stitches small and even.
  • After every few stitches, gently pull the thread to close the opening, and finish by knotting the thread inside the fold so the knot stays hidden.

Threading and hiding your starting knot

Cut a length of thread about 18 inches long and thread it through your needle. Tie a knot at the end. The knot needs to stay hidden inside the fold of fabric, so you'll start by pushing the needle through the fold itself—not through both layers.

Position your needle at one end of the opening you're closing. Push the needle into the fold of fabric (the turned-under edge) and slide it along inside the fold for about half an inch. Bring the needle back out through the fold at the point where you want to start stitching. The knot will stay inside the fold and won't be visible from the front.

The basic slip stitch motion: across, in, slide, out

Once your needle is out of the fold on one side of the opening, bring it straight across the opening to the fold on the opposite side. Insert the needle directly into the fold on that side, as close as possible to where your thread emerges.

Now slide the needle inside the fold—not through both layers of fabric, but along inside the fold itself—for about a quarter inch. Bring the needle back out through the fold. You've now completed one stitch: across the opening, in through one fold, slide inside, out through the fold.

Repeat this pattern along the entire opening. Each stitch should be small and even, roughly a quarter inch long. The smaller and more consistent your stitches, the stronger and neater the seam will be.

Keeping tension even as you close the opening

As you work, don't pull the thread tight after every single stitch. Instead, complete three or four stitches, then gently pull the thread to draw the opening closed. This gives you control over how the fabric comes together and prevents puckering.

If you pull too hard, the fabric will bunch and the seam will look uneven. If you don't pull at all, you'll reach the end of the opening and realize it's still gaping. The goal is to close it gradually as you stitch, so by the time you reach the end, the opening is already sealed.

Finishing and hiding your final knot

When you reach the end of the opening, make one final stitch and bring your needle out through the fold. Before you tie off, slide the needle inside the fold for another half inch or so, then bring it back out. This creates a small loop of thread inside the fold.

Bring the needle back through that loop and pull gently to create a small knot inside the fold. Repeat this once more for security. Trim the thread close to the fold. The knot will stay hidden inside, and the seam will look seamless from the front.

Common mistakes and how to avoid them

The most common error is stitching through both layers of fabric instead of sliding inside the fold. If you see thread on the front of your work, you've gone through both layers. Slow down and make sure the needle is traveling inside the fold, not across it.

Another frequent problem is pulling the thread too tight too soon, which creates puckers and distorts the fabric. Pull gently and gradually, checking the front of your work as you go. If you see bunching, loosen the thread slightly and adjust the fabric before continuing.

Uneven stitch length also shows, even though the thread is hidden. Keep your stitches consistent—about a quarter inch—and your seam will close smoothly and look professional.

When to use a slip stitch versus other hand stitches

Use a slip stitch whenever you're closing an opening and want the seam to be invisible from the front. This includes closing the opening on a stuffed pillow, finishing a hand-sewn hem, sealing the edges of appliqué, or closing the gap after turning a fabric tube right-side out.

If you're sewing a seam that will be visible and you want it to be decorative or functional on the surface, use a running stitch or backstitch instead. The slip stitch is specifically for hidden seams, so it's the wrong choice if you want the stitching to show.

Frequently Asked Questions

Can I use a slip stitch on a sewing machine?

No. A slip stitch must be done by hand because the needle needs to travel inside the fold of fabric, which a machine cannot do. Some machines have a blind hem stitch that mimics the appearance of a slip stitch on a folded hem, but it's not the same technique.

What happens if my stitches are too big?

Large stitches create gaps in the seam, and the opening can separate again after washing or use. Aim for stitches about a quarter inch long. Smaller stitches are stronger and look neater, though they take longer.

Do I need to use the same thread color as my fabric?

Yes, because even though the stitch is hidden, thread that doesn't match will show at the edges of the opening. Use thread that matches your fabric color as closely as possible.

How do I fix a slip stitch if I make a mistake?

If you notice a mistake while you're still working, carefully pull out the stitches with your seam ripper or a small pair of scissors, then re-stitch that section. If you've already finished and notice a problem, you can carefully open the seam and redo just that section.

Can I use a slip stitch on stretchy fabrics like knit or jersey?

Yes, but be gentle. Stretchy fabrics can distort if you pull the thread too tight. Use the same technique but pull even more gradually, and check the front frequently to make sure the fabric isn't puckering.