Sleeves, Triangles, and the Arc T-Shirt

Last week’s post had (I thought) satisfied the head-scratching on using triangles as sleeves. But was it “correct”? Here’s a quick re-cap:

It started from this cutting layout in the book Zero Waste Fashion Design. It’s the Arc t-shirt by Holly McQuillan. It uses the 4 triangle-y corners to make the sleeves, which are inserted into the slit-shaped armholes.

This is how I thought the sleeves might be formed:

Here it is tried in fabric, full-scale. It works OK, although I’m not sure how to control the width of the sleeve for different sizes.

I realised I’ve used the same idea to make the sleeves on the Xanthea top, but the triangles are cut from rectangles:

After writing the post, I corresponded with Holly McQuillan, who gave a long and helpful response.

The sleeves are much simpler; I totally over-thought it. A pair of triangles is sewn together to make a bigger triangle.

The tip of the triangle goes at the top of the armhole (which is a slit), and the other two ends overlap in a kind of spiral. You can overlap them more for a narrower sleeve and make the armhole smaller, or less and make it wider.

I made the Arc t-shirt from the Zero Waste Fashion Design book to try out the sleeves. It was really fun to sew! Below is the sleeve pinned in, but it’s very narrow even though the armhole slit is a reasonable depth.

While writing, Holly remembered a later version which has a gusset for the underarm to aid fit.

The gusset is cut off the top of the sleeve triangle, which gives a more rounded top of the sleeve.

I pinned this into the armhole (but not the gusset yet) and it’s much improved:

She said the gusset is important to longevity, and so is the positioning and circumference of the sleeve, otherwise it’s too hard to wear and gets damaged easily. Earlier versions of the sleeves were too narrow and placed too low, so there wasn’t enough arm lift/mobility.

I’ll write about making the Arc t-shirt in a future post. Unbelievably, I did everything Holly cautioned about – I cut the armhole slits too low and made the sleeves are too narrow (although they’re still only pinned in), making it impossible to wear at the moment although it’s very fixable.

Cheers! Liz


  1. Pam on October 26, 2023 at 9:50 am

    Thank you for finding out the correct answer for us! I actually tried something similar to it and dismissed it as “too small”. I still think your tube version has great potential and would love to see how it looks on the garment as a comparison.

    • lizhaywood on October 26, 2023 at 4:58 pm

      Thanks Pam. I might end up unpicking the triangles and using the tube version on the dress, or at least trying it out.

  2. Adele Fletcher on November 4, 2023 at 11:48 am

    It’s kind of magical how flattening and rounding off the apex makes the sleeve head shape look more conventional and provides a gusset.

    • lizhaywood on November 5, 2023 at 5:27 pm

      Yes – two benefits in one!

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