Dyeing the Blues

Posted by Helen

Here is Maureen delighted with the colour of her hand spun yarn at the Dyeing the Blues Workshop

Yesterday I held the last of a series of natural dyeing workshops held in the studio here over the summer. This one was Dyeing the Blues and covered dyeing with a variety of sources of indigotin. I decided to roughly follow the path that dyeing the blues would have taken in history. so we started by picking woad ( Isatis Tinctoria) and the Chinese Woad (Isatis indigotica) which turned out to be covered in lots of green caterpillars happily munching away. We tore the leaves up,having removed the caterpillars, and covered with boiling water. After twenty minutes we squeezed out the leaves and added washing soda to the liquid. I put in a bit too much and the pH was 10. My students energetically beat the liquid and the froth turned an astonishing deep deep blue. I had never had this before. Was it the time of the year? The hard beating? Or the unusually high pH , I usually have a pH of 9). Unfortunately I took few photos. I find it difficult to take photos at workshops as I am always racing around keeping everything running smoothly so there were none of this stage. I added thiourea dioxide to reduce the vat

The next vat was an introduction to a fermentation vat. I had a large one with about 9 litres in which was a madder/bran vat started four day ago. This too produced very dark blue fibres nearly a midnight blue. The indigotin in this vat came from Indigofera Tinctoria.

My students then made a stock solution also with indigotin from Indigofera Tinctoria ready to make a modern vat and we went off for lunch.

After lunch we dyed with the woad vat. This gave a deep blue the deepest colour I have ever had from fresh woad leaves. I have included a photo of the increasing depth of colour from repeated dippings from a previous workshop as a pointof comparison . The woad dyed the equivalent of no 10 ( reading from left to right starting at the top left).

Time seemed to vanish and we rushed around dyeing with what I described a Modern Vat or Chemical Reduction vat, before galloping back out into the garden at high speed at about 2.45 to gather Persicaria Tinctoria ( the Japanese Polygonum Tinctoria). We gathered two armfuls of these stripped off the leaves then all five of us chopped away with scissors. I covered the leaves with water and acetic acid and then kneaded the leaves. We strained the leaves and then I kneaded the leaves again just as I would have kneaded bread and added the resulting liquid to the rest in the bucket. We stuffed in silk, and wools and even one hank of tencel before leaving it to go back to more dyeing indoors. Finally at nearly 4 o clock we found all our fibres in the Persicaria Tinctoria had turned a beautiful turquoise and everyone was pleased and excited (especialy me as this was only the fourth time I had used the fresh leaves to get turquoise with one failure.) Below is a silk cap on the left, handspun tencel yarn ( spun by Maureen) and Teeswater curls on the right.The photo below shows the bucket after dyeing which today has gone a deep blue with grains of stuff on the bottom which I assume is indigotin settling out.

This photo is of all the colours of day. The bright greens were golderod overdyed with indigotin from the woads

The pan below is the Persicaria Tinctoria vat today.

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