Indigo pigment
I’m trying to use my Japanese indigo (Persicaria tinctoria) before frost hits and kills it, and it won’t be long. I planted it late this year and have only managed 5 ‘picks’ which were made around 15 days apart, to allow for regrowth. I had enough prepared work to dye in the first vats, but for the last two ‘picks’ there was nothing ready. Not wanting to waste the precious crop I have endeavoured to make pigment, which basically involves reducing (by evaporating) the indigo, in its alkaline, oxygenated state, down to a thick paste, and then powder. This can be reconstituted into a dye vat at a later date.
A friend helped me with basic instructions but mostly I had to experiment. I probably wasted some indigo because I didn’t find a way of filtering efficiently. There also seems to be more leaf material in it than I hoped as it looked greeny-blue at paste stage. In a hot, dry climate like India shallow containers of liquid evaporate fast but here it took days, even on the top of the central heating boiler. It was a race to evaporate the goo before it went mouldy. I forgot to weigh the leaves but I think there was about 1 kg, which reduced to 5.3 grams of indigo pigment. There is a full explanation of the way I process Japanese indigo before the evaporation stage here so I won’t repeat the method.
Bideford Black
With pigment-making on my mind, I went to see the new exhibition at the Burton Art Gallery and Museum at Bideford. It’s called Bideford Black: The Next Generation and it centres on a rare and beautiful black earth pigment which emerges from the North Devon cliffs. In the past ‘Biddiblack’ (as it was known), has been used in paint manufacture, for making mascara, camouflaging military vehicles, in boatbuilding etc., and commercial mining for it continued until 1969. Artists working in a traditional manner, or with traditional materials, have valued its velvety dark strength and subtle tones. I had a chance to try it in the Burton Gallery last week, as can all visitors to the show. Bideford Black: The Next Generation is an unusual and unconventional exhibition and it’s certainly not traditional: participating artists responded to the pigment in diverse and often thought-provoking ways. Links below.
I wanted to find out if the pigment could be painted onto sized cloth and the exhibition organisers offered me some Bideford Black to take home and try out. Using a rare pigment 300 million years old was moderately inhibiting and my efforts also felt stuffy and old-hat after seeing the exhibition. Nevertheless, stuffy and old-hat is what I do, so I got on with it.
Using the soya milk recipe generously published online by John Marshall (see link below) I stretched and sized silk and cotton and worked experimental pieces. I wasn’t trying to make anything, just seeing what the pigment would do. The black was initially ground in a pestle and mortar and then mixed with more soya milk as a binder. I found that a small amount of gum arabic assisted in holding it together, stopping moisture bleeding outwards from painted shapes. The fabrics now need to cure.
Finally in this tale of blue and black, I was lucky to book a place on a monoprint workshop run at The Burton by Grizel Luttman-Johnson. We inked up perspex plates with Bideford Black printing pigment, which Grizel had prepared by grinding and mixing the Black with a binder and linseed oil. We then placed paper on the inked plate and made drawings on the reverse of the paper. Pressure caused ink to be picked up and an impression made on the front of the paper. The plate could be used again to pick up a ‘ghost print’, which created a kind of negative image. It was a very enjoyable day, well-led by Grizel.
Some links to the Blog for Bideford Black: The Next Generation
Next Generation: Artists Selected
Related links
Teachers’ Resource on North Devon Minerals
I am indebted to Michel Garcia and John Marshall for their freely published information:
Information on Michel Garcia’s DVD on natural dyes here
John Marshall instructions for making soy milk here