Here is a photo of one flower, laid on alum mordanted wool fabric in the middle of a circle of eucalyptus leaves.
So many petals and such a bright orange, I thought these marigolds would easily be able to dye the thin layer of wool fabric underneath them. After rolling and tying up the fabric and simmering it for an hour, then leaving it to cure for a few days, I found the eucalyptus leaves had printed beautifully, but there were no marks at all on the wool to show where the marigolds had been. Still, hey ho, very few plants have a sufficiently intense dye concentration for contact printing. With my expectations downgraded and the sun blazing the whole way through July, it didn't seem too much to ask that a solar jar full of marigolds would dye a measly 10g of alum mordanted wool and silk fibre.
Somewhat baffled, I thought it might help to have a proper look at the dye. No shortage of new flowers blooming and the sun still shining, so last week, I simmered a big basketful of marigolds in a pot of water. After sieving out the flowers, the remaining fluid looked, well, just like water - see the sample in the jar on the left? When I added some dissolved soda ash to the jar on the right, it turned bright yellow, convincing me there was actually dye in the dye bath. Big smile, I reckoned that all this time, my miserable results had been down to having the wrong pH for marigold dyeing. Haha - I put several teaspoons of soda ash into the pot and added a mere 10g of wool before simmering it in the alkaline dye for an hour. This time, the fibres turned a marginally deeper yellow than the wool from the solar jar. I'm disappointed. According to the book, marigolds should be able to dye their own weight of fibre a strong greenish yellow. Probably I've been growing the wrong species. No more casual picking up of seed packets with pretty pictures in the garden centre. Next year, I shall be buying the old classic pot marigold, Calendula officinalis. Though the ones in the garden do look lovely.