Underlining! If there is one step that takes a garment from homemade to couture, it is underlining. If you sew and don’t know about underlining, once you try it you’ll see that it makes all the difference in the world in your quality.
Underlining is often also known as flat lining, interlining, or innerlining. Not to be confused with interfacing (which provides stability to specific parts of the garment), underlining is a layer of fabric that is attached to the entire back side of each piece of the fashion fabric. It is hidden inside the garment, between the fashion fabric and the lining.
The advantages to underlining a garment are numerous. So much so that I have been stuck trying to write this blog post. It seems more like something I should teach a class on!
Here are a few of the highlights of adding an underlining to your garment:
1) It gives extra body or stability to the garment. Underlining can make a flimsy fabric substantial. By the fabric you choose as your underlining, you can change the hand of the garment to be exactly what you desire. You can even have different underlinings for different parts of the garment. Maybe you want a sturdier bodice, but a lighter sleeve. In that case, maybe you’d use muslin or flannel as your bodice’s underlining, and silk organza in your sleeve.
2) It is the base for all of your internal stitches. For example, hem stitches need only to go through the underlining layer, leaving your fashion fabric free from any pricks at all! This creates a flawless finish.
3) It provides a hidden and sturdy base for closures, stabilizers, and fashion details. You can hide boning channels, interfacings, stays, horsehair trims…
4) All of your markings are on the underlining, so you don’t ever have to worry about your marks bleeding through to the right side of your garment.
And those are just a few of the advantages!
So why don’t people who sew use this technique all the time? Well, it does take an extra layer of fabric (so extra expense) and it is time consuming because it must be done by hand. But when you consider all of the advantages, it often saves you time in the long run! And it can be fun!
(Update: For a newer and more in depth series of posts and a how-to video on underlining, start here!)
For Lila Rose’s dress I was able to use our mockup dress as the underlining! Muslin seemed like a perfect match for our cotton sateen, and it was already marked and cut, saving time and money.
After our fitting, I marked my pattern corrections onto the mockup dress. I then took it completely apart ironing each piece flat. I rolled out my fashion fabric and laid out the muslin pieces carefully onto the backside, making sure all grainlines were matched.
Then, I pinned the fabrics together and cut them out!
I did this with every piece of the dress whether it was the bustle, or the train, or the sleeves, or the accent fabrics…
The next step is to baste by hand the two fabrics together. I baste just outside the stitch line. That allows me to leave the basting stitches hidden inside the garment and there’s never any reason to take them out.
I also threadmark important lines that I will want to see from the outside during construction. The photo above is of the back of Lila Rose’s bodice. I will be attaching the orange panels from the outside, so it was important that I know exactly where the top and inside of the panels will go. These threads will be removed after the panels are beautifully attached.
Once I got all my pieces underlined, I was able to hang them and make sure that the two pieces were joined absolutely perfectly. You almost always have to adjust a little, as fabrics shift in the process.
From now on, the two fabrics are treated as if they are one. You’ll see more of how underlining is crucial to a couture garment as Lila Rose’s unique dress progresses!
For a newer and more in-depth series of posts and a video on underlining, start here!
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13 Responses
What a pleasure this must be for Lila Rose! This is truly a valuable service. I cannot help noting the contrast to the miserable experience depicted in the television program “Say Yes to the Dress”.
Thank you for sharing this work.
Wow! I didn’t know about underlining yet. I have only used interfacing and a lining in a dress. Is there a reason why you need to baste by hand? I really enjoy reading and seeing what you are making!
Hand basting stitches are fairly soft and forgiving. When you baste by hand you can feel the fabrics and make adjustments to get the two fabrics working exactly together as one. There are always little adjustments to be made, sometimes causing you to pull out your stitches, which is easy if you’ve basted by hand. When you do the hand stitching, you leave the piece flat on the table, which is why it is often called flat lining. (Underlining is not something that can be done over your knee while sitting on the couch!) The two fabrics need to stay perfectly together. And it can be enjoyable once you get into the zen of it!
Machine stitches are fairly tight and can leave a ridge in some lighter fabrics. When you machine baste, it almost always feeds the two layers though the machine slightly unevenly causing corners to have slightly baggy bits. You end up having to pick out stitches and go back to the machine a lot, which could leave scarring, and really just isn’t much fun. When you stitch by hand, you are in control. When you stitch by machine, you give a bit of that control away.
Good question and thanks for reading, Becky!
Why must the underlining be done by hand?
Thanks!
Sorry for the delayed response Elaine! I was one of the thousands who lost power in the ice storm. No electricity/internet for 2 days!
And what a great question! Becky asked the same one in the comment above. Let me know if my response to Becky doesn’t make sense to you and/or doesn’t fully answer your questions. I love underlining and I want you to love it too!
Sorry to hear you were without power, but glad it’s back on. Yes, your response was helpful. Guess I should have read the comments first :). Thanks.
No worries. Thanks for asking! :)
Hi, thank you for this useful post!
My question is:
I’m making a panelled a line wedding gown in a 120g silk satin using the matte side
I realised after I’d sewn all the panels together that I should have underlined the pieces. Is it possible for me to do this now with a cotton batiste or would you recommend discarding this skirt and starting from scratch? I normally would but the fabric is quite expensive. I’d really appreciate your expertise on this
Thanks so much!
Thanks for your question Sharon! There’s no need to discard the fabric, but you will need to pick out all of your seams and iron all of your pieces back flat as if you had just cut them. You can then cut your underlining in the reverse of the way I show here. Lay out your flat silk skirt panels onto your cotton underlining (wrong sides together), then pin, cut, and handstitch the two together, just outside of (what will again be) your stitch lines. Carefully press and adjust the two layers together until they are working as one, then machine sew the panels together again. I’ve definitely done this before and though it seems like a pain, I believe it will be worth it in the end. Just find the zen/joy in carefully taking out the current seams, underlining the panels, and seaming them up again!
When applying embellishments such as embroidery or beading, would you suggest working the embroidery first, then pressing and interlining? Or basting the interlining on, then embroidering through both layers for stability?
Good question Holly! I think I’d probably underline first and do the embellishments through both layers. I’d do some samples both ways and then see what worked best with the specific embellishments and the specific fabrics.
I have some beautiful Charmeuse Silk that I want to make a summer top with. It’s a simple style, sleeveless and not too fitted, but I am wondering if I should underline it and if so what fabric should I use? The silk has a lovely soft, fluid feel which I don’t want to lose but of course it’s also quite thin (16mm weight). I have underlined cotton garments before but I’m a bit unsure about tackling the silk. Should I use another lighter silk perhaps? Any advice would be much appreciated.
Hi Frances! Thanks for inquiring!
I’ve written a series of blog posts (including a video) that goes deeper into underlining that I think you might like.
Check out: https://brooksann.com/sewing-underlining-1/
https://brooksann.com/sewing-underlining-2/ (this one has the video)
and https://brooksann.com/sewing-underlining-3/
For your silk charmeuse top, think about what qualities you want in your finished top. Does the charmeuse already have the drape and feel that you like? Then underline it with another layer of itself. Or maybe a layer of silk crepe de chine.
Do you want to change the quality of the charmeuse? Then underline it in a fabric that has more of the qualities you are looking for.
I hope this helps and let me know how it goes!