How to knit a Tortoise in n+1 steps

Tess the Tortoise

Tess the Tortoise was designed with a knit body and a ceramic shell. The shell was designed by our team’s amazing creature-creating potter, Liz Paley. The body was designed by me.

Tess the Tortoise, knitted by Kimberly A Roth
Selfie of Tess the Tortoise and Kimberly A Roth


Prior knitting experience and new challenges

While I have been knitting for a little over a dozen years and I have given a math talk about variants of a pattern, I had never designed a pattern from scratch. Like most knitters, I have made variations on patterns, and perhaps like most knitting mathematicians I have used my math skills to help make variations of patterns work, but I had never before designed a full pattern.

Likewise, I have knit stuffed creatures before, but I have rarely edited the design. I also had never used armature wire to make a poseable creature. However, having knit several monsters from the The Big Book of Knitted Monsters, which talks a bit about design, I had some general ideas about how to design Tess.

Cover of the book: The Big Book of Knitted Monsters by Rebecca Danger

Test Tess

A first attempt to knit the Tortoise out of her shell

Wire armature to support the knitted structure inside the ceramic shell
Tess Test – Armature wire for body inside shell

The first draft of Tess was made with scrap yarn and I refer to her as “Test Tess.” She was made from two different colors of scrap yarn as I depleted the first ball of yarn. The body was made in one part and the legs and head were made separately. After knitting the individual parts, I constructed the armature wire to fit the shell.

Then I made separate wires for the legs and head and stuck them inside the knit parts, added polyfill to stuff Tess’ head, legs, and body, and then sewed her up. The tail was picked up and knit on afterwards.

Test Test completed
Tess Test completed

Tess Test: the Tortoise’s evolution

Test Tess worked out better than expected, and stood on either three or four feet. The Tess team afterwards agreed on what should remain, and what should be changed:

  • the head should be larger on the actual Tess;
  • we liked the toes;
  • the final shell would be of the darker color of clay;
  • the belly would be patterned like a tortoise’s;
  • I also noted that there was more polyfill poking out than I would have liked.
Tess Test knitted with her clay shell on white background

Knitting the (actual) Tortoise

Back to basics: needles and yarn

So I used small needles to knit actual Tess, switching from 2mm diameter, size 0 needles, to 1.75 mm, size 00 ones. I charted two-color intarsia colorwork for the belly, and the body now needed to be made in two parts to accommodate that. The final yarn was picked to match the color scheme of the rest of the Mathemalchemy project.

Legs and toes

The legs required the most testing, with Test Tess trying out four different leg styles. I learned upon assembly that while having a larger foot than leg was reasonable and looked good, having a larger top of the leg made it hard to keep the stuffing inside. The biggest design decision was how to construct the toes. Everyone preferred the design with the toes, but the problem was the number of loose ends that needed to be sewn in when making individual toes. I asked around for ideas and tried picot edge toes that the local yarn store owner suggested; alas, they did not stuff well, so individual i-cord toes it was. Since each leg had four toes, the final design involved making 20 individual i-cord toes. I ended up doing this during a single Zoom work meeting.

Knitting Tess the Tortoise while attending one of our Zoom meeting
Knitting while attending one of our Zoom meeting
Starting to knit the Tortoise leg
Starting to knit Tess leg

The assembly of each leg began at the toes; first threading 5 toes onto needles in the round with alternating stitches on each needle, then a row of plain knitting, then picking up stitches between each toes, and finally beholding the ridiculous number of ends that will be yours to weave in in the future.


The top of the main body was used as a swatch for the lower body. The first draft was too big and had to be cut back. Likewise, the chart that I had drawn up for the belly was too short and I had to add rows, which I mostly did in the middle. The intarsia was a bit tricky as having up to 7 balls of yarn to work with involves a lot of untwisting and detangling.

Knitting the Tortoise's intarsia (in process)
Knitting the intarsia

Time to assemble

After overcoming all of these hitches, it was time for assembly, which involved trying to get the best lighting to see the tiny stitches in the dark yarn.

And I present to you… Tess the Tortoise

Tess was ready for her photoshoot and her place in the exhibit.

Tess the Tortoise in Mathemalchemy, walking along the Zeno's Path
Tess the Tortoise in Mathemalchemy, walking along Zeno’s Path

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