It’s not easy to dye cotton fabric a washfast and lightfast blue with natural dyes (except with indigo and woad).
After reading that iron in the soil makes hydrangea flowers more blue, I wondered if iron mordant could help to fix the blue color to cotton fabric. And after some experiments with different mordants and modifiers and various natural blue dye materials, I’ve finally found out that red cabbage dye + iron mordant produces a beautiful washfast and lightfast blue! Yay!
So in this tutorial I’ll show how to dye cotton and viscose rayon fabric blue with red cabbage and DIY iron mordant.
How To Dye Cotton Blue With Red Cabbage (DIY Iron Mordant, Cold Method)
- red cabbage
- prewashed fabric or yarn *
- DIY iron liquor
- pot and bucket
- rubber gloves
* I used unbleached and white cotton fabric, off-white rayon chiffon and white cotton yarn.
Wear rubber gloves and old clothes to protect your skin and clothes!
DIY Iron Mordant
Pour DIY iron liquor into a bucket.
Related: How To Make DIY Iron Liquor Mordant
Dilute iron liquor with enough water so that you can submerge the fabric. Wet the fabric and yarn with water, then submerge it in the iron liquor solution. Let it soak for some seconds in the iron mordant. The iron mordant dyes the fabric beige or brown.
Squeeze out excess mordant. Let the mordanted fabric dry or use it right away.
Red Cabbage Dye
Chop red cabbage and put it in cold water because natural blue colors – anthocyanins – are heat-sensitive.
I used just the limp outer cabbage leaves – the rest we used for eating.
Let the red cabbage soak till the water turns dark blue like ink. Mine took about one day.
Dyeing The Fabric
Put the fabric or yarn into the dye solution. Add water if necessary: more water won’t weaken the dye solution, but the fabric will dye more evenly. Stir the fabric occasionally. Let the fabric soak as long till you like the color – bear in mind that wet fabric is darker than dry fabric; also the color will bleed during the first wash.
I let the fabric and yarn soak for about 12 hours.
Rinse In Cold Water
The fabrics and yarn on the left are already rinsed in water. The cotton fabric and yarn took the color better than the viscose rayon which only turned pale blue.
Here’s how the fabric and yarn looked after the washing machine.
Please Pin It!
10 thoughts on “How To Dye Cotton Blue With Red Cabbage (DIY Iron Mordant, Cold Method)”
You left a comment on my blog a couple of days ago and I ended up here. You have been a lot more thorough than me with your experimenting with dyeing with red cabbage. It is quite fascinating.
Thanks for stopping by, Lesley! 🙂
Interesting and the blues are gorgeous. Pinning
Thanks for pinning, Leanna!
Fascinating that you can use red cabbage as a dye thank you for sharing Lina
Thanks, Amber! 🙂 And it’s great that the beautiful blue is light- and washfast.
This is completely fascinating to me i.e. your use of ‘iron liquor.’ I just now tried to dye a cotton shirt bluish-green using boiled red cabbage dye with baking soda. Was happy with the gorgeous color, but when I rinsed it, it all went down the drain and I was left with a white shirt again. I then read about “fixing” it first by boiling the fabric in vinegar + water before dyeing, so I tried that and this time used boiled cabbage + vinegar for a fuchsia color. After rinsing it left the fabric a light pink. Not what I was aiming for but…whatever.
I am so fascinated by your use of iron liquor, I think I’ll try making it. Then perhaps I can get one of my cotton shirts to maintain the beautiful cyan/seafoam green that comes from cabbage leaves + baking soda. Fingers crossed! *off to look for old scrap metal*
Thanks so much, Robin! 🙂 I tried different mordants too and iron liquor was the only mordant that worked. The yarn and fabric is still blue.
I tried this, and the water did not turn dark blue at all. I left it for probably 24 hours or more and the water was at most kind of magenta-ish. What did I do wrong? The water was cold, the cabbage was chopped and there was a lot of it. I dropped a bit of yarn in it, and it didn’t even color pink. No color at all.
Can you explain? Did I use a different kind of cabbage? It looked just the same as yours.
I used organic red cabbage. Non-organic red cabbage often has not enough color. And it depends on the weather and soil where the red cabbage grew. Some red cabbages that I used produced a lot of color and some not.