P.S. to the indigo/lime/fructose vat

I have now experimented with a stronger vat, this time using 2 teaspoons indigo, 4 teaspoons calcium hydroxide and 6 teaspoons fructose – that is, double the quantities used in my first vat.

I dyed the same quantities of fibres following the same methods but the depth of blue I achieved was no deeper than from the first, weaker, vat. This would indicate that this vat gives pale to mid blues but not the deep blues which other indigo dyeing methods give. I wonder whether this vat may be best used for patterning fabrics employing resist techniques, rather than for dyeing skeins of fibre as I tend mainly to do. I also noticed that this vat left the wool feeling rather harsh. However, I didn’t use a vinegar after-bath, which might have been advisable to counteract the effects of the strong alkalinity of this vat. (I never usually use a vinegar after-bath, so I’m afraid it didn’t occur to me to do so after this vat.)

If anyone else has any comments to add on using this type of indigo vat, I’d be delighted to receive them.

1-2-3 Indigo Fructose/Lime vat

I have read several times about Michel Garcia’s indigo vats – in reports from the ISEND natural dye conference in France, in posts on Helen Melvin’s blog and most recently in an article by Jane Deane in The Journal for Weavers, Spinners and Dyers. Michel Garcia is a bio-chemist who has been researching indigo dyeing for many years and he has developed indigo vats that are simple to make and ready to use in a short space of time. Michel wants his environmentally-friendly methods to reach as many dyers as possible, so I decided to try out one of his recipes and then pass on the information, so others can use it too.

The vat I have tried is his 1-2-3 vat, so called because of the proportions of the ingredients used: 1 part indigo, 2 parts slaked lime (calcium hydroxide) and 3 parts fructose. This means that for 10gm indigo you would need 20gm calcium hydroxide and 30gm fructose, for 20gm indigo you would need 40gm calcium hydroxide and 60gm fructose and so on. Calcium hydroxide or slaked lime should be available from builders’ merchants but I bought mine on the internet from Amazon. I purchased fructose from our local health food shop but it may also be available in some supermarkets. For my  trial vat I used 1 teaspoon indigo powder, 2 teaspoons calcium hydroxide and 3 teaspoons fructose.

NB Calcium hydroxide should be handled with caution. It can irritate skin and lungs and cause serious injury if it comes into contact with the eyes. Do not pour water onto it but add it slowly to water.

To make the vat, start by putting hot water (around 40C to 50C but no hotter) in a dye pot or heatproof strong glass jar. Mix the indigo powder with hot water to make a smooth paste and make sure no gritty particles remain unmixed. (Jane Deane’s article gave a useful tip for mixing this indigo paste: put the powder and water in a small container with a well-fitting lid and add some marbles (or marble-sized smooth stones). Then shake vigorously to incorporate all the indigo particles in the solution. I’ve tried this and the marbles really help to make a smooth paste.)

Add this indigo solution to the hot water in the vat or jar, then stir in the calcium hydroxide. Finally add the fructose and stir well. The vat may take up to 45 minutes to be ready but mine was ready to use in about 5 minutes. The vat can then be used in the same way as other indigo vats. One recommendation was to add the fibres dry, rather than wetting them first, but I forgot this and wetted out my wool skein automatically, as I usually do, and it didn’t appear to matter. I suspect this recommendation probably refers mainly to cotton and silk fabrics, which I often add dry to indigo vats anyway. Another suggestion was that the pH of this vat might be too high for wool. However, my vat was pH11 but I dyed wool in it without any obvious ill effects. The wool remained in the vat for about 30 minutes and dyed to a mid-blue; further dips didn’t increase the depth of blue. I also added some silk fabric and a cotton skein to the vat and both dyed to a similar shade of blue as the wool. Jane Deane’s article implies that this vat is likely to produce only pale to mid blues but the lack of a deep blue from my vat may have been because I only used 1 teaspoon of indigo to make this trial vat. Anyway, I shall experiment further with this method and see whether deep blues can be achieved.

I found this method of indigo dyeing extremely simple and effective and, if it also dyes deep blues, it could be very useful.

This shows the vat with the ingredients added

This shows the vat ready to use

This shows the wool skein in the vat

This shows the skein on removal from the vat

This shows the dyed wool skein

Dyeing with Hedge Bedstraw

I have been keen to experiment again with the native bedstraws but, since we moved house and I left my precious dye garden behind, I have been finding it difficult to harvest suitable bedstraw roots. The roots of the Lady’s Bedstraw (Galium verum) plants that I have planted in my new garden are too immature and it is against the law to uproot plants in the wild, so it seemed that any experiments might have to wait a year or two for my own plants to be ready to harvest.

However, thanks to the generosity of Leena Riihela in Finland (www.riihivilla.com) who kindly sent me some roots from her own garden, I have been able to experiment with Hedge Bedstraw, (Galium mollugo).

Compared with the roots of madder (Rubia tinctorum), bedstraw roots are very fine and delicate, and these bedstraw roots were very precious as they had come from such a long way away. So I wanted to make sure that I didn’t waste them.

For these tests I used mainly alum-mordanted wool, except for some unmordanted samples from the exhaust dyebaths. To prepare the dyebaths, I first soaked the roots overnight in water, then poured off this liquid. I then steeped the roots twice in boiling water for about 1 minute each time and added this liquid to the soaking water to make the first dyebath. I then simmered the roots twice more, using each simmering liquid for a separate dyebath. In the photos below, the orange colours on the left were from the soaking water plus the two steeping waters and also from the first 2 simmerings. I then simmered the roots again twice for about 45 minutes and used this liquid for another 2 dyebaths. The middle range of shades on the photos were from these 3rd and 4th simmerings, the redder one with an alkaline modifier (washing soda). The range on the right came from exhaust dye baths, with some unmordanted and some alum-mordanted samples. Once the fibres had been added to the dyebath, I didn’t worry too much about the temperature and allowed the dyebaths to simmer gently to improve colour take-up. (This simmering is not something I would do when dyeing with madder – see below)

I decided to work in this way, rather than combining all the extractions, because my belief is that the richest true reds lie under the yellows and browns and the best way to get reds is to first use up these yellows and browns. I don’t know whether this belief is correct but my experiences suggest it seems a good way to get reds rather than oranges. 

I now use this method when dyeing with madder and it seems to work well. After washing the madder roots well, I simmer them to extract the colour for the first dyebath, remove the roots to use again for a second dyebath and then reduce the temperature before adding the fibres.  Once the fibres have been added, I don’t simmer the madder dyebath and I keep the temperature hot but not too hot – i.e. well below simmering point. The roots can then be simmered again to extract more colour for a second dyebath. Indeed, madder is a most generous dye and the roots can often be simmered several times before the dye is exhausted, giving colour for yet more dyebaths.

I think that, when I next dye with the bedstraws, I will probably keep things simpler and try something closer to the method I use with madder. So, after soaking the roots overnight,  I will simmer them once for about 30 minutes and use this solution for my first dyebath. I will then simmer the roots again (probably for about 45 minutes) for a second dyebath and to make sure no precious dye is wasted, I will simmer the roots at least once more for a further dyebath. But first I must wait for my bedstraw roots to be mature enough to harvest.

A range of shades from Hedge Bedstraw (Galium mollugo)

A close-up image of some of  the Hedge Bedstraw colours.