Recently I was asked to dye some samples using safflower petals from Nepal. The dyed samples are to be exhibited at Edinburgh Royal Botanic Garden as part of an exhibition highlighting the flora of Nepal.
Safflower is a thistle-like plant and nowadays it is grown mainly for the oil from its seeds, which is used in salad oils and margarine. It is also occasionally referred to as “bastard saffron” because it is sometimes used as a substitute for the true saffron from the stigmas of an autumn-flowering crocus. Stems of safflower are often sold for dried flower arrangements.
Safflower has been used by dyers for centuries. It was one of the dyes identified on early Egyptian textiles and in the East it was also used to make pigments and cosmetics. Safflower is remarkable because both a yellow and a red dye can be extracted from its petals.
The photo above shows a range of yellows and reds from safflower petals.
The red dye was used from early times in India and Japan to dye cotton and silk shades of vibrant pinks and orange-red, which tend to fade with the passage of time and frequent exposure to light. The yellow dye, although deep and brilliant at first, also has relatively poor fastness. The red dye from safflower was used to dye the tapes tied around legal documents – hence the term “Red Tape”.
To dye with safflower, use at least equal weights of dyestuff and fibres. (Stronger colours will result if you use twice the weight of the fibres to be dyed.) No mordant is required for pinks and reds. Although no mordant is necessary for yellows, using an alum mordant will improve fastness.
Note: the same petals can be used for both yellow and red.
The yellow dye can be applied to animal and vegetable fibres. The red dye, which is applied at room temperature, is suitable for cotton, linen and silk, but not for wool, which does not take up the red colour.
Dyeing reds with safflower is not straightforward, so below are some details.
First of all the yellow dye must be extracted from the petals. It is advisable to wear rubber gloves or your hands will become stained. Tie the petals up in a piece of muslin or old net curtaining and immerse this bag of petals in a bucket or bowl of cool water and leave to soak for a while. Then start to press and squeeze the bag to extract the yellow dye. Remove the bag from time to time to check how much colour is still running out. When the water in the bucket is strongly coloured and the petals no longer yield much yellow dye, squeeze out the excess water from the bag. Remove the petals and put them into a pan or plastic container and reserve the yellow dye for a dye bath later.
To extract and then apply the red dye, first cover the petals in your container with enough cold water for your subsequent dye bath. Then add enough washing soda to bring the solution to pH 11 and turn the petals reddish-brown. Leave for about 1 hour, then squeeze the petals well and strain off the liquid. Don’t throw away the petals because the same petals can be used again for paler pinks, following the same processes.
Then add enough clear vinegar or lemon juice to the strained-off liquid to bring the solution to pH 6. It should now be bright red and ready for use.
Do not heat the dye liquid, but add the fibres and leave them to soak for several hours or overnight. Rinse well and dry away from direct sunlight.
Silk treated in the red dye bath becomes coral or orange, rather than pink. This is because the acidic dye liquid that contains the red dye also contains a second yellow dye, which is taken up by silk but not by cotton.
The photo above shows from the top: coral/orange on silk and red on cotton
To produce pink shades on silk an extra procedure must be followed. First add some cotton fibres to the red dye liquid as above and leave them for several hours or overnight to absorb the red dye.
Then discharge this red dye from the cotton fibres back into a solution by placing the dyed cotton into an alkaline solution of water and washing soda at pH11. Soak the cotton in this solution for about 30 minutes or until the solution becomes red.
Then remove the cotton, acidify the solution to pH6 as described above and add the silk fibres. Leave them to soak until they have become pink.
The photo above shows pinks on silk after the extra step.
Dyeing yellow with safflower petals is much simpler. Put the dye liquid into a dye pot, add the fibres to be dyed and heat to simmering point. Simmer for 30 to 45 minutes then turn off the heat & allow the fibres to cool down in the dye bath. Then remove them and wash and rinse them.
This photo shows a range of yellows from safflower on wool (top), silk (centre) and cotton (bottom)