The slip stitch (the invisible one)
Okay. Pants are pinned, you looked before you touched a needle, and now we're actually sewing the hem. This is the stitch that makes a hem disappear. It's called a slip stitch, sometimes a blind stitch, sometimes people call it a blind hem stitch and it's all the same thing, so don't let the names throw you.
And here's why it matters: a hem you can see from the outside looks like a mend. A hem you can't see just looks like pants.
What you need
- Your pinned hem, folded and ready from last time
- Thread matched to the fabric — not too thick, or it'll show through
- Needle threaded, elbow-length thread, knotted
- Good light. This one's fussy and you need to see what you're doing.
The stitch itself
You're working from the inside of the garment, hem folded up and pinned in place.
- Come up from inside the fold of the hem, hiding your knot inside the fold where it'll never be seen.
- Now catch just one or two threads of the outer fabric — the part that shows when you're wearing the pants. Just a thread or two. Not a bite. A nibble.
- Then go back into the folded edge of the hem and travel maybe a quarter inch, staying inside the fold, and come out again.
- Catch another thread or two of the outer fabric. Back into the fold. Travel. Out again.
You're basically zigzagging between the fold and the outer fabric, but almost all of your stitch is hidden inside that fold. The only part anyone could ever see is that tiny nibble of thread on the outside, and if you're catching one or two threads, it's not visible. Not from three feet away. Not from three inches, if you did it right.
Keep your tension loose. This is not a stitch where you pull tight. If you pull tight you'll pucker the fabric and then it's not invisible, it's a hem with a frown on it. Let the thread lie there loose enough that the fabric hangs the way it wants to hang.
Where people go wrong
They rush the "catch a thread or two" part and grab a whole chunk of fabric instead. That shows. Every time.
They also pull the thread tight after every stitch like they're lacing a boot. Don't. Loose. The hem should have a little give in it when you're done, not be cinched down like a drawstring.
And they use thread that's too heavy for the fabric — we talked about matching thread to fabric a few lessons back, and this is exactly the lesson where it comes back to bite you. Heavy thread on a lightweight fabric will show through no matter how careful your stitch is.
Which reminds me — I have never fully lived down the time I got this wrong on purpose, more or less. William had a temple shirt that needed a button reattached the morning of a sealing, of all mornings, and I grabbed thread that I thought was white. It was a hair too cool, a little blue-white against the warm white of the shirt fabric. Nobody else noticed. I noticed for the entire session. Couldn't stop looking at that button. Changed it that night. So — match your thread to the actual fabric, in real light, not what you think "white" means off a spool. Store lighting lies to you and so does your memory of what white looks like.
A note on speed
This stitch is slow. Slower than you want it to be. That's fine. Slip stitching a whole hem might take you twenty, thirty minutes depending on the size of the garment. You are not behind. This is what the stitch costs, and it's worth it.
When you don't need invisible
Here's an opinion of mine and I'll say it plainly: a visible mend is not a failure. If you're hemming work pants or something a kid's going to destroy in three weeks anyway, you don't need the slip stitch. A regular running stitch or even a machine hem is completely honest and fine. Save the slip stitch for the things where it matters — church clothes, good pants, anything going in a photo. Sunday best gets sunday best stitching. Everything else just needs to hold.
Safety note
Your needle's small and your stitches are tiny and close together, which means your fingers are close together too. Go slow enough that you're not stabbing your own finger through the fold — it happens more with this stitch than almost any other because you're working blind, feeling for the fabric instead of watching it.
Before next time
Try this on something low-stakes first — an old pair of pants, not your good ones — so your hands learn the rhythm before it counts. 🌷
- V