I love simple, seasonal dye experiments that feel a bit like slow alchemy — especially when they use things I’d otherwise compost. Recently I’ve been playing with dyeing linen using onion skins and black tea, deliberately skipping chemical mordants so the process stays accessible, low-waste, and safe for a small kitchen setup. Linen takes dye beautifully and its natural texture gives a rich, lived-in result that I always find irresistible.
Why onion skins and black tea?
Onion skins are one of my favourite natural dyes: abundant, free (if you save peels), and capable of producing lovely warm golds, ambers and rust tones. Black tea adds depth and softens the warmth into more muted, vintage-inspired hues — plus it’s a pantry staple. Both materials are gentle and safe to handle, and when combined they can give a range of lovely neutrals on linen without using mordants like alum.
What to expect (colour outcomes)
Natural dyeing is wonderfully unpredictable — the exact shade will depend on your linen (bleached vs. unbleached), how long you simmer, and the strength of your dye bath. As a guide, here’s what I usually see:
| Material | Typical Result on Linen (no mordant) |
|---|---|
| Onion skins (yellow onion) | Warm golden-yellow to burnt-sienna |
| Onion skins + black tea | Soft warm beige, antique tea-stain, light brown |
| Black tea alone | Pale tea-stained beige, subtle vintage wash |
Materials and tools
Here’s what I use for a small-batch experiment (enough for a linen tea towel or small cushion cover):
- 100–300 g linen fabric (prewashed)
- Approx. 100–200 g dry onion skins (yellow onions work best; red onion skins give pinky hues)
- 4–8 strong black tea bags (or 30–60 g loose leaf)
- Large stainless-steel or enamel pot (dedicated for dyeing)
- Wooden spoon, tongs, heatproof gloves
- Strainer or muslin bag for peels
- Optional: baking soda or vinegar for simple pH adjustments (see notes)
Preparing the linen
Prewash your linen in warm water with a mild detergent to remove finishes and starch. This helps the fibres accept dye more evenly. I always wash items I plan to dye twice: once to clean and once just before dyeing so the fabric is thoroughly wet — wet fibres take up dye more evenly.
Making the dye bath
1) Rinse onion skins to remove dirt. Place skins in a pot and cover with cold water (allow space for fabric). Bring to a gentle simmer for 45–60 minutes to extract colour. If using a muslin bag, place skins in it for easier removal.
2) Add the tea bags or loose tea for the final 20–30 minutes of simmering to deepen the tone. For a more golden result, omit or use less tea; for cooler, tea-stained tones, increase the tea quantity.
3) Strain out the solids and return the liquid to the pot. Don’t discard the spent skins — I often compost them or reuse them for a second, lighter dye bath.
Dyeing without mordants — how the colour sets
Traditional mordants (like alum) anchor pigments to fibres. Without mordants, the dye relies on direct absorption and the natural affinity between tannins (in tea) and linen. Black tea provides tannins that act like a mild natural mordant, helping the onion-derived pigments adhere better. The trade-off is that colours will be softer and potentially less wash-fast than chemically mordanted pieces, but they have a beautiful, lived-in patina that I adore.
Step-by-step dyeing
- Wet your linen thoroughly and squeeze out excess water.
- Place the wet linen into the warm (not boiling) dye bath. Keep the heat at a gentle simmer — aggressive boiling can stress fibers and create uneven dyeing.
- Stir gently and keep the fabric submerged for at least 45 minutes to 1 hour. For deeper shades, leave the fabric in the cooled dye bath overnight (room temperature) — I often do this.
- Check colour by lifting a small portion when cool enough. Remember it will look darker when wet and will lighten as it dries.
- Rinse the fabric in cool water until the rinse runs clear-ish. Hang to dry away from direct sun to avoid fading while wet.
Tips for stronger, more even colour
- Use a high dye-to-fabric ratio: more skins/tea per fabric weight gives richer tones.
- Keep fabric moving gently in the pot to avoid uneven patches.
- For very even, muted tones, allow the fabric to cool in the dye bath for several hours or overnight.
- If you want warmer, rustier tones, try including a small amount of rusty nails wrapped in muslin in the bath — this is an old trick to introduce iron, which shifts colours toward deeper browns. Test first on scraps.
Lightfastness and washing
Natural dyes without mordants can be less lightfast and more prone to fading with frequent washing. To care for dyed linen:
- Wash gently in cool water on a delicate cycle or by hand with a mild, pH-neutral detergent (I like Ecover or a soap-free wool wash).
- Avoid chlorine bleach and high heat in tumble dryers.
- Turn items inside out and wash with similar colours to prevent staining other garments.
Safe practice and sustainability notes
I always use a pot dedicated to craft dyeing rather than my cooking pans. While onion skins and tea are food-safe, the residues and any added metallic items (like nails) mean I prefer to keep kitchenware separate. Compost spent onion skins, or use them to enrich your garden — gently strained dye liquid can be diluted and used to water non-edible plants; test cautiously.
Variations and experiments to try
- Red onion skins can yield pinks and mauves, especially on lighter or pre-treated linens.
- Try overdyeing: dye linen first with tea, then with onion skins (or vice versa) to layer tones.
- Add plant leaves or flowers to the fabric before simmering and bind them with string for simple eco-printing effects.
- Adjust pH with a splash of vinegar (more acidic = warmer, redder tones) or a pinch of baking soda (more alkaline = greener/browner shift). Always test on scraps.
Quick troubleshooting
- Patches or uneven colour: Fabric wasn’t fully wetted, or the dye bath temperature varied. Try pre-wetting thoroughly and keeping a gentle, steady heat.
- Colours too pale: Increase dye material quantity, simmer longer, or leave fabric in the cooled bath overnight.
- Excess bleeding on first washes: Expect some loss. Rinse thoroughly after dyeing and wash gently to remove unfixed pigment.
If you’d like, I can share a printable recipe with specific weights for larger batch dyeing (e.g., 1 kg linen). I often keep a little notebook of experiments: dates, onion type, tea strength, time in bath, and resulting swatch — it’s the best way to learn how your materials behave. Dyeing this way feels slow and forgiving; each piece comes out with its own personality, which I find much more satisfying than factory-perfect uniformity.
