Archive for June, 2017

More thoughts on the 1-2-3 lime/fructose indigo vat

Monday, June 26th, 2017

I have been looking at various recipes for the 1-2-3 lime/fructose indigo vat, which was developed by Michel Garcia, and I made one interesting observation – in most of the recipes, the fructose (which is the reducing agent) is added before the lime (calcium hydroxide), which is the alkali. This surprised me as, when making 1-2-3 vats, I always add the alkali first. I wondered whether I was alone in this, so I was pleased to find that in Helen Melvin’s recipe the alkali is also added first. Helen is a very experienced dyer, with extensive practical knowledge of various types of indigo vats, and she has also attended courses led by Michel Garcia, so I felt I was in good company.

So why should I be surprised to find so many recipes in which the reducing agent is added before the alkali? Firstly, because it goes against what is, I think, the usual practice when making indigo vats; for example, when making an indigo stock solution, the alkali, in this case caustic soda, is added before the reducing agent; and when processing fresh woad leaves to make a vat, the alkali is added to the solution before the reducing agent. Indeed, the alkali is added first when making most types of indigo vats, so why would one change this order? The other reason why changing the usual order seems to me illogical lies in the name “1-2-3” vat, which seems to me to suggest that one would first add to the water one part indigo, then secondly one would add two parts lime (calcium hydroxide), the alkali, and thirdly three parts fructose, the reducing agent, thus maintaining the neat 1-2-3 order of both the proportions of ingredients and the order of adding them. (And also adding the ingredients in the same order as with other types of indigo vat.)

So does it actually make any difference whether one adds the alkali or the reducing agent first? One way to find out would be to do some experiments, so I made two small sample vats, for one adding the ingredients in the 1-2-3 order and for the other adding the ingredients in the 1-3-2 order. Otherwise, exactly the same weights of ingredients were added to each vat.

The photos below show the results. In each of the photos, the 1-2-3 order vat is on the left and the 1-3-2 order vat is on the right. The photos show the gradual progress of each vat and the final test samples. The vats each took about 1 hour to be ready for use.

The results indicate that the order in which the ingredients are added seems to make little, if any, difference to the final results. Although the vats didn’t look exactly the same at each stage, the dyed samples show that each vat produced samples of almost identical shades of blue. So I shall continue to add the ingredients in what seems to me to be the most logical order: 1-2-3.

For further information on indigo vats, see Helen Melvin’s excellent book “Indigo; The Colour of the Sea and Sky”, available from Helen at Fiery Felts (link on the right under “Useful Links”).