A few years back I grew some marigolds. As the blossoms drooped I harvested them and dried them, but then stuck then in a cupboard and forgot about them. In a fit of boredom during the rains this year, that kept me inside more than I am used to, I discovered them and decided it was time to use them. I boiled them for a couple of hours until the water turned a deep golden brown, strained off the liquid and sealed it in a gallon jar.
Then came spring and summer with days of soaring temperatures that once again kept me inside. I spent some time spinning a fleece that had waited for me for several years. I plied a small one-ounce skein to see how I liked it and hit on the brilliant idea of using my marigold liquor to see what would happen. It was too hot to turn on the stove for this experiment so I decided to go solar. In a small jar just large enough to hold the skein, I dissolved a scant half teaspoon of alum in water and added a pinch of tartaric acid. In went the skein, on went the lid, and out it went to a table in the yard to sit in the sun for a day.
The marigold liquid had developed a layer of mold on the top, but it peeled of easily in one piece. The mordanted skein now went into this dye bath for another couple of days in the sun. And it seems to have worked.
Now on to the next step. I am not sure what that will be.