So … How to Block a Side Seam on Your Underwear and Stop the Flipping Drama!? 🤔
Let’s be real for a second – is there anything more annoying than finishing a gorgeous pair of handmade knickers, putting them on, and feeling that side seam flipping back and forth like a fish out of water? 🙄 Honestly, it drives me mental. You spend all that time choosing the perfect lace or fabric, and then the seam decides it wants to live its own life. Not on my watch!
Hi, I’m Alyona! If you’re new here, a massive welcome to the family. 🙌 I’ve been sewing since I was old enough to hold a needle without poking my eye out. I remember exactly how frustrating those early days were – the “what on earth is this” moments and the ruined fabric that ended up in the bin. I’m here to spare your nerves (and your fabric) so you can get straight to that professional, “did I really make this?” result without the meltdown.
In this guide, I’m spilling the tea on how to block your seams in two different ways: by hand and by machine. If you’re ready to level up your lingerie game, you can even grab the free printable panty pattern to practice these techniques on 🧵!
The Golden Rule of Side Seams
Before we even touch a needle, let’s talk about the one rule you must never break. All side seams – and shoulder seams too, while we’re at it – need to be folded towards the back of the garment. This isn’t just an “underwear thing”; it’s a “making anything from a blouse to a skirt” thing.
If your seam is looking towards the front, it’s basically looking for trouble. Keep it facing the back, and your silhouette will thank you.
Method 1: The Hand-Stitched “Invisible” Fix
This is my absolute favourite method. Honestly, it’s the cleanest and easiest way to get a result that looks like it came out of a high-end boutique. Plus, there is something so lovely about sitting down with a cup of tea and a few snacks while doing a bit of hand-finishing. ☕️🍪 Time flies, and it doesn’t feel like a chore at all!
How to do it:
- Hide the Knot: Once you’ve finished sewing your masterpiece, fold that side seam toward the back. Grab a matching thread and your needle. Push the needle through from the side where the seam will be folded over. This way, when you fold the seam down, it sits right on top of the knot. The knot is hidden in the middle, and your work looks pure and professional.
- The Blanket Stitch: Now, you’re going to use a blanket stitch to secure the side seam to the back element.
- How to blanket stitch: Wrap the thread around your finger to create a loop. Push the needle through both layers (the side seam and the back element). As you pull the needle through, make sure it goes through the loop you created. It’s like a little hug for your fabric!
- The Reinforcement: Don’t just stitch the top! You need to sew along the top of the side seam and then a little bit down the side too. Only grab the first layer of the elastic – we don’t want to see any stitches on the beautiful right side of the fabric.
- The Finish: If you’re using fold over elastic or Picot Loop Elastic, the seam is usually less than 1cm. Block your thread at the end by pulling the needle out and wrapping the thread 2-3 times around it before cutting.
Method 2: The Machine-Stitch “Lace Melt”
I have a very specific rule for this one: I only use the sewing machine method when I’m working with Nylon Elastic Lace.
Why? Because if you try this on plain fabric, you’ll see those zigzag stitches clear as day, and it looks… well, a bit “home-made” (and not in the cute way). 🙅♀️ But with lace, the threads are all mixed up in that gorgeous pattern. When you stitch over it, the thread literally melts into the lace and becomes invisible.
How to do it:
- Match Your Thread: This is vital. Use the exact same colour thread as your lace. I’m obsessed with Gutermann Thread because their colour palette is insane – you can match it to the millimetre.
- The Settings: Use an elastic stitch (multi-step zigzag). If you’re not sure about your machine, check out my guide on What’s the Best Sewing Machine Settings? – I’ve had so many people tell me this turned their sewing from “Level 0” to “Rocket Scientist” overnight! 🚀
- The Stitch: Fold the seam toward the back, pop it under the foot, and stitch from top to bottom. Backstitch at the start and end to secure it.
Why Thread Choice is Everything
Listen, don’t ruin your hard work by using cheap, grumpy thread. If I want my creations to last longer than a week, I always go for Gutermann or Polyester Sewing Thread.
Never use cotton thread for underwear – it’s just not strong enough to handle the “stretch and pull” of daily life. If I can’t find a Gutermann match, I’ll use a simple nylon thread, but it must be polyester. Anything else is just asking for a “wardrobe malfunction” drama that nobody needs! 😱
I hope you found this helpful! If you want to see these techniques in action, I’m always showing them over on my YouTube channel. Go have a peek!
Now go forth and sew some non-flipping seams! See you in the next one! ✨🙌
