Introducing Project 008—Undies

Our next drafting project is for Undies, aka underwear, panties, pants, briefs, chonies, knickers, drawers etc.

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Today, I'm excited to announce Project 008-Undies! A couple of weeks ago, I posted a poll with three project options, and undies was the winner with 49% of the vote. I like this as a project because a pattern everyone can use, it’s quick to sew and you can really customize to fit your personal style.

» Update 09/2025: The tutorials for this project are now archived for paid subscribers.

If you are interested in this project but don’t want to subscribe, you can purchase a pdf version of this project in my shop.

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Drafting Reference

For this project, I’ll mostly be using the pattern drafting book Pattern Cutting for Lingerie, Beachwear and Leisurewear by Ann Haggar (on Bookshop). I’ve had this book for a few years but haven’t used it very much. My other main drafting books have sections on activewear with garments like leggings and bodysuits but they don’t do bras or undies. So, I really appreciate having this book as part of my library. And I think it has a lot of cute, fun, interesting designs.

Above are some photos from the book. I’m very curious about the French Knickers. (I think it’s similar to tap pants but with the side seams overlapped. So flirty!) I love the ingenious simplicity of the sleep-suit bottoms (last photo) but I also wonder if it would feel like wearing a diaper. Have you ever worn a garment like this?

Anatomy of the Bikini Briefs

Undies are fairly simple as patterns go, with just three pieces: a front, a back and a gusset. There are side seams and seams at the front and back of the gusset. Then the raw edges are finished with some type of elastic or a fabric band. The amount of seam allowance required on those edges will depend on your construction method.

In the illustration above, I’m showing a Fold Over Elastic finish which does not require a seam allowance to be added.

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Sewing Resources

I’ve sewn a lot of undies before and I think they are a really fun and practical way to use up scraps of knit fabric.

One of the fun and admittedly tricky parts of sewing undies is sewing with elastic. The great part is that there are lots of different options. But the tricky thing is that it can take some practice to sew the elastic. (Personally, I like to sew elastic in the round as opposed to flat.)

You can use fold over elastic (aka FOE), picot elastic or even regular 1/4” wide elastic. (FOE can also be expensive. If you are in the Los Angeles area, I recommend stocking up in the Fashion District. My favorite store for FOE is Trim 2000 Plus. They have lots of colors and it’s very affordable.)

How to Sew Undies If you’ve never sewn a pair before, check out this video from Megan Nielsen Patterns. They show how to sew a few different elastic options. If you sign up for the newsletter, you can also get the Acacia Underwear pattern for free.

If you don’t want to use elastic or don’t have access to it, you can also use fabric bands to finish the edges of the undies. Both the Super Basic Underpants pattern by Halfmoon Atelier and the Dune Tank & Brief pattern by Christine Haynes use bands or have a band finish option. Christine has a sewalong video about sewing the briefs here.

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Reference posts

To draft the undies we'll be using the negative ease and stretch fabric that I shared about in Project 005. Link below.

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Happy mathing!

Beth