frugality (blog action day - poverty)

"Frugality does not mean poverty or deprivation. It means the wise use of resources."

Paul Hawken in 'The 11th Hour'.
For full quote, see NPQ (4th from bottom).


Rather than write about poverty, the theme of this year's Blog Action Day, I thought instead I'd consider the wise use of resources as the means to avoid it. Partly I am inspired by that wonderful organisation Practical Action which devises and/or introduces very simple technologies to lift struggling communities out of dependency or poverty.

A recent mailout from Practical Action describes a fish-rice culture introduced to Bangladeshi rice farmers. A minor re-design of rice fields allows fish to also grow there. The rice thrives from the fish naturally fertilising it, consuming insect pests and circulating oxygen, giving an apparent 10% increase in yield and savings in purchased pesticide and fertiliser. As well as having fish to eat, the farmers now also grow vegetables and bananas on the dykes.

Fish-rice culture reminds me of the traditional silk production cycle – silkworms feeding on mulberry bushes, the cocoon waste following silk harvesting fed to fish in the pond, with fish waste being scraped from the pond floor annually to fertilise the mulberry bushes.

My dream is to find a similar cycle for woad production. At the moment, in theory, I can use organic chicken manure to fertilise soil (for nitrogen content). Perhaps chickens will eat post-extraction plant waste, but there isn't much of it (currently it goes in the compost bin). Perhaps as woad is such a slug-magnet there'd be mutual benefit with poultry living alongside? Whether simple or complex the cycle turns out to be, I said it was a dream and probably it will stay that way. I don't have and am unlikely to ever have enough land to grow enough woad for all my own dyeing – I will always need to buy it in.

Earlier in the year I visited Ian Howard in Norfolk, who's been at the forefront of woad revival in Britain for some years now. Since processing my comparatively meagre crop a month ago I have thought a lot about the time and effort he must put in, leading to the high cost of woad-sourced indigotin. Occasionally I've wondered whether it is really worth it... but then think back to Procion dyes and the minimal information available about its production. It means so much more to know who has grown and produced the dye and where, how, and why! To know this farmer has and is increasing specialist knowledge of the crop, knowledge that would have been garnered over generations of past woaders. To trust that he knows he needs to take care of his land in order to continue to grow it, and to maintain both quality and financial return. That must mean a wise use of resources.

Synthetic dye... dye with no entity, no place, let alone no place in nature, and virtually no history. Dye without a soul. Manufactured anonymously somewhere in the world from petrochemical from somewhere else in the world, packaged up and sold on somewhere else again. There is no trail, no depth – any dyeing from this becomes just a colour, nothing more. So how to be sure resources have been used wisely? Impossible, it seems, with Procion MX.

One is cyclical, working within nature's limits; the other based on linear production. Cyclical is frugal, implying taking only what nature can afford – some years not much, but in others a bonanza. In comparison linear can only ever lead to poverty somewhere for someone, surely?


update, midnight at end of Blog Action Day

Having spent the last hour reading other blogger entries for this day addressing poverty, I have felt moved enough to do something more (the concept of Blog Action Day works!). Instead of occasional donations I am setting up a regular payment to Practical Action. Their donation page says the following:

Please do something special today. Offer the hand of friendship to poor communities by making a regular donation by Direct Debit. Be part of the solutions that will change the lives of people in poor communities day after day, year after year.

For over 40 years Practical Action has been investing in simple and extremely effective technologies that give determined people the power to change their lives. Our experience tells us that you can’t solve poverty by giving handouts – instead we work together with people in their homes and communities, listening and learning from them. We work at the heart of desperate communities across the world, helping people to find simple, sustainable solutions to problems they face.

- We don’t believe in imposing quick fixes. So we make sure that all our projects are sustainable, use local materials and are organised and run by local people
- We overcome poverty across the world using practical, tangible and often innovative solutions. We use simple technologies and share our knowledge widely.
- We make sure that the money that funds our work goes directly to our offices in that country rather than the government, so you can be sure the money goes only to the people who need it.

getting blue!

On the tray is all the woad cut at Helen's on September 4th, about 450g. Several plants had grown better than mine, that is, they had bulked out though were still not as fully grown as expected. Others were middling, like mine, with a few well and truly eaten! But only three caterpillars emerged during the wash!

The four pots from my front garden yielded a further 50g, so in all I had about half a kilo. About half I'd been hoping for – but quite acceptable considering August's lousy weather. The left hand pile is good wholesome leaves, the top those that were fairly battered, bruised, part-eaten and part-rotting (bad bits later cut out). Can't quite remember what the right hand pile is – possibly small and slightly battered leaves.

While washing my leaves I felt they were more blue-green than Helen's, so compared them. One-all I think, if mine are bluer but hers grew better. I'll come back to the growing stuff later.

Half a kilo of chopped leaves - including stalks. I reckon stalks must contain some indigo too, and having so few leaves/weight I couldn't afford to be discriminatory.

Whisking time is telling time... when the alchemy works or doesn't. In my case I was leaping with joy to see so much blue pigment (indigotin) in the foam, and appearing so quickly! I was expecting the foam to turn 'back to green' within 10-20 minutes of whisking, but all I was getting was more and more foam, and blue. The bucket was less than two-thirds full of liquid - top third all foam! I tried scooping it off and re-whisking, I tried mixing the foam back into the liquid, I tried giving it a break for some minutes. But still foam came up good and blue. In the back of my mind was a vague memory from one or more of the various indigo workshops I've been on, where a similar stage in vat-making required stirring to introduce oxygen - and being told soon after that it had worked and I could stop stirring. And so an hour later I convinced myself that I surely had whisked enough, there certainly was blue there (and everywhere!), and I could move on to the next stage - bottling. The memory of stirring at an indigo workshop remains vague and, in the light of day (I stopped whisking around 1 am!), not making sense. Either I was confusing the process with another, or we were processing woad (or other) leaves to make indigotin without me realising. Anyway, whatever it was, it helped me at that time - I had started to think about what I was doing, the process that was happening, instead of just following instructions!

This yellowy-green is the colour of the liquid going into the jars.

Total of seventeen jars. At this stage I deviated from the instructions, which called for periods of settling and siphoning off of the top liquid, followed by a consolidation of all bottom liquids into one container, with the top liquid being diluted with water and siphoned. Each time I pulled off the top liquid it was greenish, making me suspect there was 'blue' in there too. I saved all siphoned liquid, letting that too settle before re-siphoning. In all, I had three separate siphoning stages. After a few days of settling, some jars were showing a central body of amber liquid, surrounded by greener tinted liquid and a strong blue bottom layer (see previous post). It demonstrated to me that my earlier instinct was right, that the top greenish liquid had contained some blue pigment, and a longer settling time was all that was needed.

All liquid from the last siphoning went into the bucket, and a few days later when its top liquid was siphoned off it revealed yet another bottom layer of blue!

Although it obviously wasn't traditional to use filter papers, I did think it was perhaps the modern take on a traditional filtering technique - and had read it would yield more indigotin. I also thought it might yield more if I didn't repeatedly 'water down and re-siphon' the liquid, as early on the top liquid had proved to also contain blue pigment. So I started filtering undiluted liquid - some greener, some bluer. My instinct paid off again - see how golden it came out (in a beer glass from a Bodmin Beer Festival, and looks good enough to drink!).

Filtering started at a rate of about two drops a second. By the end it was one drop a minute, which is why by then four filters were on the go! But slowness wasn't the imminent problem. Soon after starting the filtering, I was wondering how to get the pigment off the paper at the end. The more I thought about it the more I wished I hadn't started down this route. Perhaps an upside is that it made me concentrate on related chemical processes to look for a solution. There may be one but far too long-winded to take seriously, though I might check it out sometime.

Two dried filter papers with skims of pigment over some, and a crust in parts. The crust cracked up like dried mud. If it had been thicker it might have picked off cleanly, but for me it took some paper fibres with it. The very thin layers I scored lightly with a scalpel before brushing the fine powder away. But some paper fibres went too. Pigment and fibres weighed in at two grams.

Four filter papers, as much pigment as possible removed. Took about a day. Now, had I followed instructions to consolidate the bottom liquid more and dilute it down with water, this end result might have been different. Probably I'd have had just one filter paper, so the pigment on it would have been thicker and more easily removable. Possibly it would have not seeped so far into the paper had the pigment been suspended in water instead of the remnant alkaline solution. Possibly... probably...

One thing is for sure though: a lot of pigment remains on the paper. This macro-shot shows how much is wasted. Criminal considering time and effort - mine, Helen's and nature's. I won't be using filter paper again.

With thanks to Teresinha Roberts, Helen (in North Wales) Melvin, and Ian Howard for various processing instructions, guidance and encouragement; to Ian Howard, Isabella Whitworth, Vivien Prideaux, and Abi Evans for past indigo workshops which helped develop my understanding of the indigo-making process; and to Ian who supplied the seed I grew. And not forgetting members of the Natural Dyers list. Special thanks go to my good friend Helen (in North Cornwall) for patiently growing, watering and de-slugging my woad plants over the last few months.

shredded woad

Helen, who is growing most of my woad for me, emailed a bit despairedly on Monday. Slugs being the main cause, and her concern that I wouldn't have any leaves left come harvest time. I popped over that afternoon, the following photos are from that visit. These first four show various stages of shreddedness... but most plants were doing just fine.

And so... slug control: Helen has access to sawdust, I have access to coffee grounds so we are trying both. The coffee was applied just before this photo around up-till-then unprotected plants. Most successful seems to be a copper ring (top and bottom right), but only a few plants have these, and only one has broken eggshells (white). Research suggests that coffee grounds release nitrogen into the soil, an element apparently loved by woad - or rather its uptake increases eventual pigment quantity. I've also read that coffee grounds have an anaerobic effect if applied too thickly, and that it's either acidic (which can't be too good when your soil is already acidic) or breaks down to neutrality (which shouldn't matter). There is more to consider though than woadish preference - nitrogen broken down by bacteria forms nitrous oxide (N2O), a far more potent greenhouse gas than carbon dioxide. Not being a chemist I'm really not sure of the pros and cons of using it as slug repellent and soil fertiliser, or even of growing nitrogen-loving woad itself... but I will find out! At least the coffee grounds (like the sawdust) are already waste products that would eventually decompose anyway.

Helen has created three plots for the woad. The first is in a spare part of her raised walled veggie garden - I think she said courgettes were growing there until the slugs got 'em. The next is a raised bed that last grew potatoes; and the third is part of the bank that had been covered by carpet to kill couch grass (roots were dug out before planting). All sites get loads of lovely sun... and rain, it being the Cornish summer holidays now.

And finally, four of my five potted plants. Three are teenagers now and allowed out all night but the fourth (back left, in ceramic pot) is still a kid and comes in around midnight. A few days ago I came home feeling so unwell I didn't have the energy to bring it in... and yes, the slugs took advantage. But it's still growing. The fifth plant is elsewhere with the tomatoes and aubergines, a different mini-climate, so I can see how location changes growing patterns. All of mine have had coffee grounds protection from their first venture outdoors.

woad dyed samples

Two pictures of woad dyed samples from the workshop at Woad Inc last April. Following dyeing they were rinsed umpteen times in water with Ecover, with a final rinse in vinegar (as advised for indigo by Vivien Prideaux). The vinegar rinse seems to stop further dye washing off, somewhat magically to a non-chemist! They haven't yet been boiled to remove wax but being rinsed in hot as well as cold water most has already gone. When I have enough to justify boiling up the burco then they'll get boiled out.

Woad Inc's vat was already made. Alkalinity was raised to pH9 with soda crystals and Hydros added to remove oxygen. The vat was steaming away, at 55 deg C. I was concerned it was too warm and would make the wax melt. Some dye was taken out and cooled to 35 deg C in its new bowl. This was used for dyeing the four prima, in a series of dippings, as shown in the first picture.

This cotton had no initial scour: the samples went straight in the vat (after soaking in water). Each group dip lasted approximately a minute, then the samples hung to air for up to another minute. So the lightest piece had only one approx-minute dip, and the next darkest two dips etc, up to four. There seems little difference between third and fourth dips - I am putting this down to my bad approximate timings or alternatively, lax control over which piece went in or came out first. It was all rather rushed. However, the colour is nicely even and for what it was meant for, the test has worked well.

The six organic cottons plus prima (non-organic) as control had substantial scouring, based entirely on trying to make powerloom evenly absorbent. On this test I was successful, despite being over the top! I washed the cottons 'with agitation' in hot water with Ecover. Following a rinse they were left to soak in hot water again with Ecover over two nights. They then were well-rinsed individually, followed by a 10-hour soak collectively in water, powerloom soaking separately. And rinsed again before hanging to dry. Whilst most of the cottons didn't need this treatment, subjecting them to the same ordeal as powerloom was necessary for making comparisons after dyeing.

These seven text pieces, shown in the second picture, were dyed in the formally too-warm vat, which had cooled to 45 deg C, after a soak in water. They had one collective dip, for approximately 10 minutes (despite then having a timer, I managed to not set it properly, so still no accuracy over timing). Again, I was uncertain which went in first and which came out last, though I think I gave powerloom longer.

Sadly, all seven pieces have not dyed evenly, including the test prima. Ian at Woad Inc believes this is related to air (ie oxygen) somehow being introduced to the dye bath - such as clumsy insertion of cloth. This might explain why powerloom has dyed so badly in the past - if it has been unable to absorb water then air must be in the fabric instead thus introducing it to the dyebath? But it also could relate to clumsy handling in the dyebath - cloth touching other cloth. Or back to the scour... should I have used Ecover? Was the three days soak in water alone sufficient for powerloom, or something from the Ecover not quite rinsed out despite my best efforts? Was it because the samples were dipped for 10 minutes? Was it the higher temperature? Certainly there's a difference between treatment of the two primas to make one dye evenly and the other not. Of course I kick myself that I didn't dye the organics in the same vat as the prima four-dip-series. It would have rule the vat out straightaway. I welcome any suggestions those more experienced in indigo dyeing can give...

Also worth commenting on is that the intensity of colour of the 10-minute dip prima is roughly the same as the twice-dipped-for-a-minute-each-time prima. Is that temperature-related, time-related, dip number-related or scour-related?

Memories from indigo dyeing with Abi Evans (outdoors) is that cotton was dyed cooler than animal fibres. With Vivien Prideaux and Isabella Whitworth (see here and here) their vats were blanket-wrapped but otherwise room temperature (though looking back through notes I find conflicting advice). But perhaps woad-sourced indigo acts differently, does require more heat? Although chemically the same as indigo-sourced indigo there may well be other things 'human expertise' doesn't understand about it (in the way that DNA was not mappable a decade or so ago).

Well, the answer is to get my own vat set up and find out! I haven't been able to yet, due to getting work done on the house, the tax return, and sowing of woad seeds that friend Helen will be growing for me. Frustrated that I can't get on with dyeing due to 'other stuff' I also am borecd of doing sample pieces only... it's also time to start developing designs appropriate for blue-chromism.

soda ash - where from, how, and what is it really?

The early part of February was taken up with investigations into soda ash, that versatile white powder used not only with fibre reactive dyes as a "fixative" but also as a traditional and versatile household chemical. The article was published in the March 2008 Batik Guild magazine and is also available on my website. There was a lot for me to get my head around, and indeed I needed (repeated) assistance to grasp some of the chemistry. Looking back to my first delvings into soda ash last July I realise that what the article doesn't do is assess the sustainability of using the chemical - in end use in dyeing and scouring (or by inference household use) and through sourcing and manufacturing. The trouble is I'm not confident or clever enough to draw conclusions, only to take them from published research. And I don't know if there is any.

However, I have no problem 'feeling' my way... science is all very good and proper but there is nothing like trusting instinct for getting it right.

After I'd finished the article I sat back and while resting my tired brain considered my earlier thoughts on the white stuff (pre-July 2007). I hadn't really thought about it, of course, but had a vague inkling it was naturally mined something like salt, say. But without any regard for resource sustainability. So my research has left me gobsmacked!

Of the three processes - manufactured (as in UK), mined (as in eg, US and Kenya), and 'gathered' from kelp or salsola ashes (the Old Days) - I cannot say with any certainty or feeling which is the most sustainable. But I've a feeling that at quantities produced globally today, none are. In line with everything else... I feel very uncomfortable at the thought of ripping out Mother Earth's innards, as required to retrieve limestone and rock salt for manufacture (but recognise my hypocrisy as today I put 33 more litres of petrol in my car without flinching). I'm less sensitive to surface mining of trona or natron as they are naturally renewing resources, but I feel Nature is hard pushed to keep up with our consumerist demands. Burning plants would seem the most eco-friendly resource as their annual replenishment is easy to gauge and thus Nature would set the limits. But... 'society' would collapse and (new) resource wars break out if this became soda ash's only source.

I need help to get answers, obviously.

loose dye update 2

A few weeks ago I uncovered the reason for the loose 'magenta' dye, forever slightly washing out but not seemingly weakening the colour on the fabric. Or rather I didn't uncover it, it was explained to me by Stuart at Kemtex... With Procion MX, small amounts of both 'magenta 'and 'cyan' dyes (but especially magenta) continue to move around the fabric a bit when drying. Thus when re-wetted they will rinse out.

It reminds me of warnings on labels in red clothes in days gone by, to always wash reds separately not with other colours, and of ensuing white pinkiness when the warning hasn't been heeded. I think non-MX Procions are used for clothes-dyeing these days which eliminates pink residues.

I did find cyan ('turquoise' in MX parlance) washed out initially then stopped, then magenta ('brilliant red') took over. At least there's no need to keep testing for errors in my dyeing ways. Although I'm a bit annoyed at the time-wasting, there are benefits in that I've learnt more about MX requirements along the way.

Stuart said there is a cationic fixing agent available on the market (and at Kemtex) which is supposed to address this loose-dye situation. Formerly this was formaldehyde based but due to environmental reasons no longer is (info on formaldehyde here and here). Although it resolved washfastness issues it compromised lightfastness so wasn't that wonderful anyway! The new version isn't formaldehyde, but I don't know what it instead IS.

A couple of websites list similar sounding products, Fineotex in India, and Shanghai Tuebingen, a Chinese subsidiary of German company CHT, who make Rewin.

Rewin ST seems the most promising, mentioning the difficult dyes by name but will give "slight shade changes". Slight changes could be catastrophic if a perfect harmony or balance of colours was intended but was then altered. What is so good with Procions is the brilliance of the colours, that complimentaries (or other pairings) can really sing and vibrate against each other. Take that edge away and the whole appears flat and lifeless. Fineotex NFE is apparently eco-friendly but we have only their word for that (or maybe not even that: "the information is in good faith but without warranty"). It doesn't say if it will affect lightfastness or change colours.

Anyway, as my Procion batiks are generally never re-washed after framing there seems no reason for me to need (read 'risk') this additional fixing solution. Or waste world's resources.


I also learnt from Stuart where their MX is made - Indonesia (he did tell me the company name but I'm not going to reproduce it here obviously!). Indonesia is an obvious place for it to be manufactured, considering how much batik is made there and it being an ideal cold water dye that won't melt wax. Stuart assumes it is also still made in India.

indigo and organic cotton

Last week I went on Vivien Prideaux's two-day indigo workshop in Plymouth, part of the inspiring touring show 'Indigo' currently at Plymouth City Museum and Art Gallery. And last Tuesday I had a truly wonderful indigo dyeing day working alongside friend and fellow batikker Isabella Whitworth. I feel I have come on in leaps, bounds and confidence since my first few forays into indigo dyeing with Abi Evans some years ago, which is great because that's what workshops are for!

The experience making up and working with my own vat yesterday was elating, also disturbing as I realise I don't have space for ongoing indigo dyeing here. The mess! Vivien meant it when she said indigo would get everywhere. Isabella and I worked in her double garage with tarpaulins on the floor to catch drips and hold puddles. Abi also worked in a garage sized space and outdoors. When I move, if I don't acquire a garage I will certainly need space for a garage sized shed just for dyeing. For now I had pondered doing it in the kitchen near the back door, and close to the drying line outside... but not now I've remembered what a messy person I am! Small scale my tiny bathroom could be OK, but as I don't really work small scale it won't. Why not in the studio itself? Easy! Don't want a wet floor - it's carpeted (in a fashion). Nor do I need stray indigo powder/granules/streaks/smears popping up all over...


Vivien and Isabella worked their vats in different ways to reduce the indigo (to a soluble state suitable for dyeing, by de-oxygenating the water). Vivien used lime and zinc dust, and Isabella hydrosulphite and caustic soda (as did Abi). "Zinc lime" is, I think, the traditional way still practised by some village craftsmen/women but commercially has been replaced by the "hydros" technique. Vivien indicated that hydros is more reliable but by using fierce chemicals is less environmentally friendly. Both need more research on my part to understand the sustainability issues.

Vivien had two vats already on the go which needed re-activating (that is, re-de-oxygenating) and Isabella made hers up fresh that day (though as mine wasn't "exhausted" by the time I finished will re-activate it another time). Vivien had one natural and one synthetic vat, Isabella's were synthetic though she also uses natural indigo. So, I've been lucky to have experienced both within a short space of time. Vivien's explanation of the difference between natural and synthetic starts in its mode of production – natural indigo is derived from the indigofera species of plants, extracted from its leaves and stems; synthetic is pure chemistry – nothing more or less than the exact chemical formula that is pure indigo – petro-chemically derived. Natural indigo isn't pure - its impurities are what gives it its character... such as colour varying slightly. With synthetic you get digital perfection each time, predictable and measurable.

My inclination is that production of synthetically-produced indigo is probably no better and may be worse environmentally than fibre-reactive dyes; on the other hand only a finite amount of natural indigo can be produced each year (without encroaching on food crop land), and although at a low price in the west because of being imported from lower cost countries, its relative scarcity should be recognised by being used only in dyeing "things" that carry a value of their own - not a financial value but a respect or spiritual value, a value for community and future generations. I am not sure where my work fits into that yet but I know what I shouldn't be doing! Ideal would be a vat that can be replenished/re-activated over and over rather than making up a new one each time, that is if I convert completely to indigo-dyed batik. Having to take regular care of a vat would ensure a good relationship with it, one that wouldn't treat the dye as commodity. To contrast, it's hard to not view synthetically-produced, market-quantified dyes as commodities, and with that attitude how could I really put 'mana' into my work?

Most of the first day of Vivien's workshop was taken up with shibori – aaagh... sewing! Needle, thread and I do not good companions make, but I worked diligently throughout the day only getting narked at going-home time when finding the thread used wasn't adequate for puckering up the cloth. I unpicked all my samples at home that evening and by 1 am had re-made them all with proper-puckering embroidery thread. Although the shibori part of the workshop didn't particularly interest me I do believe in making the most of opportunities to learn new skills, they can open new ways of thinking or approaches (eg, I see now how it's possible with thread and puckering to make cloth three-dimensional, even though that wasn't the intention here). The second day was dyeing day. And my sewing worked – brilliantly in some cases, I humbly thought! Big mistake though was to not sketch, photograph or otherwise note down the technique used in each for future reference. Too much in a rush to get to the vat, I think.

As well as dyeing the shibori pieces I tested small samples of the organic cottons with mixed success. With so many others using the vats it was impossible to do a controlled kind of testing. They were getting exhausted too quickly (they=vats not participants!), and although all took the dye some are far paler than others. So I carried out this testing again at Isabella's, with 2 five min dips on each. These samples were boiled first in soda ash water to scour them. Additional sample pieces that had only been washed in warm water with soda were also tested.

At Isabella's I also dyed a 2 x 1.2 metre length of prima, to get a grasp of vat size. The tub began with about ten litres of dye, which had reduced a bit by the time of the first dip, and a bit more by the third. Dry, the cloth shows uneven dyeing streaks at one end. Although all the cloth was below the surface, the cloth/dye/tub ratio wasn't high enough to ensure all was opened out and able to absorb dye. A deeper vessel containing twenty litres dye would be my next aim, along with a contraption to hold the cloth open top and bottom as it goes in – research and design cap needed!

Today is washing out day... more to follow.

top pic - shibori and indigo dyed pieces drying at Vivien Prideaux's workshop. Mine are just right of centre stage, hanging on the looped railings.
middle pic - Isabella Whitworth amongst her batikked and dipped indigo scarves (pre-dyed in annatto). The vat I worked with is under the blanket inside on the right.
bottom pic - My organic cotton tests drying at Vivien Prideaux's workshop

ashes to soda ash

Bang goes my hypothetical reed bed plans... soda ash is toxic to aquatic life! Pretty obvious really, considering its multiple uses as cleaner. According to the Fine Chem Trading's MSDS the toxicity comes from "a damaging action due to shift in pH". So all dye rinse water that contains soda ash fix must go down the mains drain for treatment and not be used for watering the garden (OK, mine isn't an aquatic garden but it does rain-a-lot in Cornwall and, well, it might eventually filter through to the village stream.) Also, here on Bodmin Moor the soil is acidic - Ansac's MSDS indicates that soda ash can react violently with strong acids with, uh oh, none other than carbon dioxide (and heat) evolving. Maybe the moor isn't acidic enough for that, but I'll stick to the mains!

Na2CO3. Sodium carbonate. It was the chemistry that got me into researching soda ash. More specifically the carbon aspect. What does happen to it – errr, it doesn't go into the atmosphere hopefully? And, well, where does soda ash come from? Is it natural-ish or entirely man-made?

Before soda ash, potash (potassium carbonate) was the alkali equivalent. It was extracted from wood fire ash with water; later soda ash was found in the ashes of certain salt marsh plants, also in kelp ashes. This is really exciting news - I could make my own soda ash, maybe with strandline kelp! Ashes from a beach barbie kelp fire!

But, as it seems with everything, more questions emerge. Would producing my own kelp-derived (soda) ashes release more carbon into the environment than the commercially produced ones? Would the amount of strandline kelp I'd need deplete this mini-marine ecosystem faster than it could be replenished? Would the amount of calorific energy I'd need to get to (probably) Crackington Haven to gather kelp and stoke a fire outweigh the oil-based energy required to bulk manufacture and ship the soda ash from factory to my house via the supplier?

I'm not going to try to answer these! Just keep in mind that soda ash can be derived from kelp ashes. As an aside, I was once told Procion dyes' chemical structure is derived from kelp's.

Anyway plant-ash derived soda ash soon couldn't keep up with C17 European demand (or plant "replacement" couldn't?), and physicists began researching artificial production. Frenchman Fresnel discovered in 1811 that carbon dioxide bubbled through brine containing ammonia created sodium bicarbonate (NaHCO3) and from this sodium carbonate is derived. The process was commercialised in 1864 by Belgian Solvay. Using ammonia doesn't sound too pleasant but most is recovered and recycled. Carbon dioxide and water are also are recoverable and re-used. Calcium chloride, the main by-product, is sold as road salt (hold on... I thought mined rock salt provided that), and the only raw inputs are salt, limestone and some form of thermal energy.

The process involved:

CaCO3 goes to CO2 + CaO
calcium carbonate goes to carbon dioxide + calcium oxide

NaCl + CO2 + NH3 + H2O goes to NaHCO3 + NH4Cl
sodium chloride + carbon dioxide + ammonia + water goes to sodium bicarbonate plus ammonium chloride

2 NaHCO3 goes to Na2CO3 + H2O +CO2
2 sodium bicarbonate goes to sodium carbonate + water + carbon dioxide

2 NH4Cl + CaO goes to 2 NH3 + CaCl2 + H2O
2 ammonium chloride + calcium oxide goes to 2 ammonia + calcium chloride + water

The Solvay Process Wiki explains this chemistry more fully, and Solvay SA's soda ash website informs about all stages in the process. For instance, their salt is extracted from underground salt mines through solution mining; coke is used to fire the kilns that decompose mined limestone into lime and carbon dioxide; ammonia and carbon dioxide are recovered for re-use in a distillation process...

The Solvay process predominates production worldwide, except in North America where trona-derived production has replaced it - mainly because the production process is cheaper. Trona is a naturally-occurring mineral found in non-marine evaporated deposits. The US has the world's largest resource in Wyoming, with enough trona to supply the world for 1300 years. Apparently. A batik artist wouldn't use much of that but it's still a finite global resource if mined faster than replaced. The Wyoming trona was laid down 50 million years ago as a large lake in the Green River Basin evaporated.

Trona is Na3HCO3CO3.2H2O and needs a bit of work to bring it down to Na2CO3. The Solvay SA website explains the trona process well, clearly demonstrating the simpler procedure compared to the Solvay process.

I have to admit to being a bit bamboozled by all this chemistry... and what it means for me as a simple artist so am going to post this now and come back when I've dug and thought deeper.