Medieval yarn dyeing

Laura Yarrow
6 min readOct 3, 2020


A crafty day out at Cranborne Ancient Technology Centre

I thought it might be interesting to write about something other than UX, service design and research for once, so here’s a short segway into some of the crafty activities I got up to one sunny weekend near Cranborne, Dorset.

If you’ve met me you’ll know I have a love of all things woolly, so a day out learning how to dye my own wool using medieval techniques was hard to pass up. We had our medieval experts Kat Stasinska and Monica on hand to show us the techniques, teach us the history, and make sure we didn’t make a mess! (or poison each other, eek!).

Getting started

The venue is at the amazing roundhouse in the Ancient Technology Centre, an evocative location for this sort of workshop. Monica got the fire going that would heat our pots to hold our dyes and yarn…

We were given 9 undyed yarn samples that we would be putting in various pots of dye. They were numbered with little christmas trees as you can see in the above photo. The pots were left to warm by the fire — we didn’t want them to boil, just reach a nice hot temperature which would help release dye from plant fibres once they were placed inside. If you love your yarn, you’ll know boiling wool is not a good idea, unless you wanted a felted fluffy mess!

Top of the roundhouse roof — smoky!

Learning about the techniques and looking at samples

Kat had helpfully laid out lots of samples she had pre-dyed with the “recipe” and process she used, so I spent a bit of time snapping those to try out later. It’s amazing that some of the depths of colours that have been achieved just from using natural dye-stuffs.

Samples using all natural dyes — various yarns, linens, silks and threads.

After a bit of explanation about how natural dyeing works, it was time to go out and find our own fibres, all under Kat’s carefull guidance of course! We also wanted to collect some water that had been infused with iron from the blacksmiths tools, as this can be used as a mordant to fix the colour of the dye to the fibre. I liked Kat’s description of how this lets the colour “bite” onto the yarn 😊

Kat’s on a mission to find plants! Out of our way sheep!

The ancient technology centre has lots of different plants that are useful, and we were on the look out for woad and weld. These are ancient plants that have been used for centuries, for all different reasons. You’ll probably recognise woad as the blue dye warriors decorated themselves with before battle. Although woad is tricky to spot, apparently it is part of the cabbage family and smells a little like that too. Luckily Kat knows her stuff and we managed to find some!

Clockwise from top left: Woad! Kat picks weld, a madder root, and collecting water with iron particles in from the blacksmiths hut.

The gardens at the ancient technology centre are beautiful and stuffed full of different interesting plants. The buildings there are amazing too, and there are sheep all over grazing, it was so serene and beautiful. In such a short space of time I learned a lot about the different types of plants and their uses.

Not sure whether to be alarmed or intigued by all these bones hanging around…

Extracting the dye

Next was time to feel like a mad scientist and extract the dye from the plants we collected. This is the fun part, as there is so much natural variation you can’t be certain what you’re going to get. We also set up the pots with our mordants in to show how using different ones and the same dye-stuff will change the colour significantly. We used the iron water in one pot and some special moss in the other. These would allow us to soak the undyed yarn in them, before rinsing and putting the mordanted yarn into the dyestuff to see the variation in colours.

By far the most interesting one was woad — it was literally like magic! The leaves are torn and left to steep in the hot water, then whisked (with authentic medieval whisk fashioned from branches and twigs!!). The foam that is produced as oxygen is introduced was amazing, bright blue! What was quite exciting is that as you draw the yarn out of the dye bath it looks fairly pale, but it got darker after a few seconds. It’s a beautiful colour to obtain from a fairly innocuous looking green plant.

Bottom: Woad leaves that have steeped and now being whisked, Top: the blue colour obtained from this method!

At the same time we also put some dried madder root into pots to steep — this was not collected on the day as you need so much of the plant to get a small amount of dye, and so it would have taken most of the day to collect! This was one of my favourite dyes as with the iron mordant some of the samples came out a beautiful rich plum-pink colour, and this changed depending on the type of yarn used and length of time left steeping.

Some of the variation achieved with madder and different moss and iron mordants. Check out those blues from the woad though!

We also tried weld but this didn’t come out as bright as Kat had hoped, it possibly was because the flowers had died off the plant mostly due to it being later in the year (Autumn). I managed to over-dye the weld coloured yarn into woad and make a beautiful sage green though — like I said, it’s magic!

Weld in the pot, and being poured into a new pot whilst being strained with a crocheted sieve — very medieval and authentic!

Another interesting experiment was with peeling the skins off walnuts and using those to create a dark brown dye — anyone who has ever peeled a walnut will know that they stain your hands and it’s very hard to get off again! That produced a wool sample that is really dark brown, very nice. Here is the full spectrum of colours achieved on the day and all the samples and extra bits of undyed yarn I brought with me:

A beautiful yarn rainbow! Pinks: Madder, yellows: weld, browns: walnut, olive greens: weld + woad, blue: woad (all using a variety of mordants to get the different shades).

This really was the most magical day, in the best setting, with a great tutor. As soon as I got home I started planning my own yarn dyeing escapades — which i’ve since had some success with (and not) — but that’s a post for another day!

If you’d like to learn more or buy some of the things she makes, here’s Kat’s website: Medieval Colours 👏👏👏



Laura Yarrow

UX and tech geek. Observer of humans. Crisp connoisseur. Yarn fondler. Undercover Northerner.