Holly McQuillans spiral trousers

In the world of zero waste pattern cutting, Holly McQuillan’s spiral trousers are considered a must-do/bucket list pattern.

These unusual trousers have been on my mind for some time, but I didn’t feel brave enough to try them until I saw Sue Stoney’s blog post on them and saw Holly demonstrate how they’re constructed at an online zero waste workshop.

The pattern appears in the book Zero Waste Fashion Design as just a layout and a garment sketch. It doesn’t have measurements or sewing instructions; it’s offered as a starting point for experimentation.

However, others have made them: @stikleif on Instagram has made them as full-length trousers, shorts, capris, and yoga pants; Modconned wrote a blog post; Anouk van de Visch made a tie-dyed pair; Kathleen Fasanella trialed a pair in calico; and they’re on the Make/Use website. The #spiraltrousers page on Instagram shows pairs made in striped fabric. If you’re planning to make a pair, I highly recommend looking at all of these; it’s such a big help.

The legs are triangular pattern pieces – so unlike any other trouser pattern and an example of the kind of creative patternmaking wrought by the parameter of zero waste.

Here are the pieces cut out:

Holly McQuillans spiral trousers layout
The fabric is very old narrow cotton, which happened to be the exact width I needed! It looks the same on the right and wrong side.

Below is an explanation of the pattern pieces. Each triangle is a leg, with the crotch cutout being used for pockets. You can see that the ankle is on the bias and the waist is on the straight. The waist isn’t actually half the waist measurement; it just wraps half way around the body and needs darts to fit it to the waistband.

Holly McQuillans spiral trousers sketch of pattern
CF = centre front; CB = centre back.

The spiral seam gets sewn like this, and spirals its way around the leg to the ankle.

Holly McQuillans spiral trousers sketch sewing the spiral seam

Here’s a short video showing the spiral concept:

I pinned together the spiral seam first and tried the trousers on, and immediately discovered the ankle was too small. It only measured 11cm across and I just couldn’t squeeze my foot through!

Holly McQuillans spiral trousers tight ankle opening

So I unpinned them a bit to get them on. The fit was quite good.

Holly McQuillans spiral trousers pinned together
Holly McQuillans spiral trousers pinned together back view

Then I went off for a bike ride to think through the ankle problem.

I had been very cautious about not stretching the diagonal side of the spiral seam, and even notched each side at 20cm intervals so I could match it properly. But what if that’s a bad idea and it’s better to let the bias stretch? That would give a bigger ankle section.

I unpinned then re-pinned, disregarding the notches: 13.5cm ankle.

I actively stretched the bias edge, then re-pinned again: 15cm ankle.

Fourth and final effort: 16cm. Victory! I put a 32cm notch along the bias edge for the ankle.

However, by stretching the bias edge into submission, the seam bulges on the straight grain side because I’m essentially easing it on. After a good press this didn’t look as bad on the finished trousers, and for my second pair I topstitched both sides.

Holly McQuillans spiral trousers pinned together
These are still pinned together, but you can see the bulges on the seam.

UPDATE: something to try next time is to convert the excess fabric into a dart that’s somewhere at knee level.

This wouldn’t be a problem for larger sizes or elastic-waisted versions, because the angled edge would be longer, giving a longer ankle section.

One of the restrictions with this pattern is that you’re cutting two legs the same, not a pair. To get paired legs, either the fabric needs to be the same on both sides so that one can be flipped (which is what I did) or you need to cut two trousers the same with the fabric paired. Further down this blog post I experimented with adding an extra seam to use fabric that has a right and wrong side.

Once the pattern is sorted, it’s quicker to sew than regular trousers. I sewed the spiral seam on each leg then proceeded as per usual for trousers (zip, waistband, hem).

I was very happy with how mine turned out and I’m wearing them now as I write this! They’re very comfortable and don’t feel any different to wearing regular-cut trousers.

Holly McQuillans spiral trousers navy
Instead of a zip I made a front placket with buttons, involving a happy half hour sorting through the button jar for an (almost) matching set.
Holly McQuillans spiral trousers navy
Here’s the back view, where you can see the top of the spiral seam at the centre back.
Holly McQuillans spiral trousers navy


In case you’re thinking about making these and want to cut down on the amount of trial-and-error involved, fyi here’s how I did mine:

I made a paper pattern for the trousers, but you could draw them straight onto the fabric if you record the dimensions and make a template for the crotch cutout.

Holly McQuillans spiral trousers sketch of size
These are the dimensions I made my pattern.
The width was 84cm/33″ to fit my 101cm/40″ seat/hips. You can see from the above photos how much room this gives – I probably wouldn’t want them any closer fitting. For bigger sizes, I would increase it 1 1/4″ per size (ie, if you have 42″ hips, make it 41 1/4″; for 44″ hips, make it 42 1/2″, etc). Of course you could make it bigger than this.
I took a 1cm seam allowance on the spiral seam.
The 145cm length was barely adequate, and I could only do a 1cm hem. I’m 168cm/5’6″ tall. You’ll notice that 145cm is waaaay longer than you’d normally cut trousers length at, because the spiral seam loses length as it winds around the leg.

To get the crotch shape correct, I used a trouser block that I knew fitted.

Holly McQuillans spiral trousers crotch curve
The trouser block didn’t have seam allowances so the black line shows where I would draw the line.
From memory I think I straightened up the centre front crotch so it wasn’t angled slightly like the block is.
If you don’t have a trouser pattern handy, you could trace the shape off a RTW pair that fits.

Here’s what the top of my pattern looks like. You can see there’s a side dart (to shape the waist in lieu of a side seam) and a back dart. To decide on the darts, I cut a waistband to fit my waist then darted the trousers to fit:

Holly McQuillans spiral trousers pattern

If you wanted to make an elastic waisted pair, the top edge (minus the crotch cutout) would need to be at least half your hip measurement so that you could get them on:

Holly McQuillans spiral trousers sketch for elastic waist


Using fabric with a right and wrong side

I wondered if, by adding an extra seam, a single pair of spiral trousers could be cut from fabric that has a right and wrong side.

Here’s the idea:

Holly McQuillans spiral trousers sketch single face fabric experiment

But that means there would now be two diagonal seams radiating from one’s butt – how would that look?

Well, you’ve gotta try these things!

I added onto my pattern so that there would be enough for the extra seam allowances needed:

Holly McQuillans spiral trousers sketch of taupe trousers

I used some taupe cotton drill, slightly heavier and crisper than the navy cotton.

Holly McQuillans spiral trousers taupe cutting layout

After seaming the pieces back together again, I laid them on top of each other (paired) and cut the crotch curve:

Holly McQuillans spiral trousers pair of taupe legs

I think it turned out okay!

Here’s where the seams end up – the black line is the spiral seam and the white one is the one I added. I pressed both seams open and topstitched 6mm on both sides:

Holly McQuillans spiral trousers taupe

Here’s what the back looks like:

Holly McQuillans spiral trousers back view of taupe
Holly McQuillans spiral trousers taupe
Holly McQuillans spiral trousers taupe
I did a zip fly front on these.
I haven’t put the pockets on these yet, but I will before I wear them properly.
Holly McQuillans spiral trousers taupe


The verdict: highly recommended for a unique trouser sewing experience!

Cheers!

26 Comments

  1. Anna on February 15, 2021 at 5:22 pm

    Thank you so much for the explanation, really helpful, tempted to try myself now. Yours look great and comfy, I’m off to check out the insta hashtag now.

    • lizhaywood on February 15, 2021 at 7:13 pm

      Ah, just go for it Anna!

  2. Claire on February 15, 2021 at 5:57 pm

    These are definitely on my to make list. I love your hack to make a pair. I have similar hip/ height measurements to you So I may use yours as a starting point

    • lizhaywood on February 15, 2021 at 7:18 pm

      I wish I’d made these sooner! Hope yours turn out really well too.

  3. annie on February 16, 2021 at 1:52 am

    Que faire d’un rectangle de tissu ? Eureka ! , C’est super, merci pour l’idée et les explications…

    • lizhaywood on February 16, 2021 at 11:28 am

      Pas de quoi!

  4. Michelle Cahill on February 16, 2021 at 5:13 am

    Also on my sewing to-do/wish list. Brilliant work!

    • lizhaywood on February 16, 2021 at 11:28 am

      Thank you! Hope yours go well!

  5. Sue Harper on February 16, 2021 at 7:51 am

    Thanks for writing this up Liz. This is such an intriguing idea. My measurements are similar to yours, but I’m 5’10 , most of that is in my legs, to the point that the need for pants long enough got me into sewing as a teen. I’ve got this on my bucket list!
    Any comments on varying the length?

    • lizhaywood on February 16, 2021 at 11:31 am

      Thanks for reading Sue 🙂
      I would make mine 150cm long next time. To make them longer, you’ll need to add 1.5 times the amount you want eg – for a 10cm longer leg add 15cm.

  6. Beth Powell on February 16, 2021 at 2:53 pm

    Great post Liz. Thank you so much for sharing. I’m going to give these a go now 🙂

    • lizhaywood on February 16, 2021 at 4:21 pm

      Cheers Beth, so glad it was helpful.

    • Morag on February 17, 2021 at 7:43 am

      Fab post Liz, it all makes sense now! I did wonder about the legs being the same and couldn’t work it out at all but that is super clear

      • lizhaywood on February 17, 2021 at 10:43 am

        Cheers Morag!



  7. Meta on February 16, 2021 at 7:09 pm

    These were on my wish list, thankyou so much for this, very helpful!

    • lizhaywood on February 16, 2021 at 7:13 pm

      You’re welcome!

  8. Esther on February 17, 2021 at 4:22 am

    Your idea of cutting 1 pair of fabric with right and wrong side is so clever ! I might want to try another pair

    • lizhaywood on February 17, 2021 at 9:36 am

      Your Instagram pairs were sooo good!

  9. Anna on February 17, 2021 at 8:22 am

    Thank you so much for all the infos! I was dreading to try these trousers because of the try and error factor * time spent. This post will be soooooo helpful! Merci <3

    • lizhaywood on February 17, 2021 at 10:42 am

      I confess that that’s what put me off making them for so long, but it really helped seeing other people’s. Best wishes for yours 🙂

  10. Janet on February 17, 2021 at 4:01 pm

    So cool! Both pairs look fabulous! Thank you for posting all the details. My measurements are similar to yours and I may use your samples as a jumping off point, as I am really intrigued!

    • lizhaywood on February 17, 2021 at 5:42 pm

      They are fun to make! Best wishes for yours 🙂

  11. Terri Gardner on February 19, 2021 at 4:26 am

    I’m behind my daughter, Michelle Cahill on this. This is the first time I have seen these and they are incredibly interesting. I would have never imagined that you could even make a zero-waste trouser. Thank you for putting down clear instructions.

    • lizhaywood on February 19, 2021 at 9:33 am

      Yes, such a fascinating and unlikely-looking pattern. I highly recommend trying them!

  12. Sal on June 9, 2021 at 5:43 am

    Wow!
    Stumbled on this while looking for cutting layouts — I always try to use the “waste” as a t-shirt or vest, but now must try this waste-free idea. Particularly like the patch pockets on the blue pair!

    • lizhaywood on June 9, 2021 at 9:10 am

      Yes, it’s a bit of a wow! pattern, isn’t it? You must try them! I’ve worn both these pairs lots (the taupe pair now has pockets) and they’re very comfortable – I think it’s because of the bias cut leg.

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