Thread Your Needle

Before you can slip stitch, you'll need to thread your needle. Double the thread, and tie a knot at the end. This makes the thread more secure and less likely to break. Snip the thread under the knot if needed, so you have about 1/4-inch thread tail.

Prepare Your Closure

Getting the closure ready is a step that some people skip, but it's the secret to getting an invisible slip stitch.

Take your item to slip stitch, and fold the fabric inside the closure to match your seam. Press with an iron or finger press to make a nice even fold on both sides of the fabric. Cut away any loose threads of frayed fabric that are close to where you will be stitching. You want a nice clean area that lays flat.

Hide Your Knot

To start the slip stitch, you're first going to hide your knot. This secures the thread while keeping it out of sight.

Starting on one side of the closure, insert your needle inside one of the folds, being careful not to come through the outside of the fabric.

Bring your needle back out through that fold toward the middle of the closure. Pull the thread through until the knot is hidden in between one of the folds.

Start Your Slip Stitch on One Side

Now that the knot is hidden, it's time to start stitching.  

Bring the needle to the opposite fold of where your knot is, and insert it into the fold. Then, bring the needle out of the fold a 1/4 inch or less away from where you just inserted it. Be sure not to catch any of the outside fabric when you make your stitch.

Pull the needle and thread through to complete your first stitch.

Sew the Slip Stitch on the Opposite Side

Repeat the slip stitch you just completed on the opposite fold, in the area that's straight across from where you just stitched. 

Keep Making Slip Stitches

Continue making slip stitches in the same manner, working back and forth between the two folds. Keep making slip stitches until you get close to the end of the other side of the closure. The closer your stitches are the more secure your seam is going to be.

You'll notice the thread goes back and forth between the folds, looking like ladder rungs. This is why the slip stitch is also called the ladder stitch. 

Knot Your Thread

Once you've reached the end of your closure, it's time to knot your thread and secure it.

Grab a small amount of fabric inside the fold with your needle, and pull your thread through just a bit, not all the way. You'll now have a thread loop that you can use to make your knot.

Insert the needle through the loop, and pull through to create a knot.

Make one more knot in the same way to secure your stitching.

Finish Your Slip Stitch

Trim the thread close to the knot. If you peek inside the closure, you might be able to see your stitches. This is fine and why you should choose a matching thread (unlike this demonstration, which used contrasting thread to show the stitches). 

Give the closure a final press. This will make it nice and crisp and hide any stitches that might be peeking through.