Qualities of Indigo

[Geowu]

Before the invention of synthetic indigo dye there were several kinds of natural indigo.

Their price was based on their quality, for instance the Indian indigo was much more expensive than the lower quality US indigo. In Japan some artisans fan the vats night and day to keep the indigo at the best temperature during the fermentation, and thus get a better quality dye.

How does synthetic indigo compares in terms of "quality" to the grades of natural indigo?

Does synthetic indigo retain the insect-reppelent properties of natural indigo?

[jdavis]

How does synthetic indigo compares in terms of "quality" to the grades of natural indigo?

There is tremendous variety in the quality of natural indigo - over 500 species of indigofera alone -the largest indigo-bearing genus. As well, the 'ingredients' of the dye vat can give equally tremendous variety to the derived indigo-dye. Unfortunately, the best answer to your question would be - it really depends on the species of indigo-bearing plant, the means by which the indigo is derived, and then the means by which the dye is reduced.

Does synthetic indigo retain the insect-repelent properties of natural indigo?

The insect-repellent characteristics that you refer to could be as much a property of the dye vat reducing agents (ammonia, sulpher, etc), as the dye itself.

[Geowu]

"The insect-repellent characteristics that you refer to could be as much a property of the dye vat reducing agents (ammonia, sulpher, etc), as the dye itself."

That's interesting, never thought about it. 45rpm claims their Natural Indigo jeans reppel insects, but they don't mention anything about the Synthetic Indigo (Sorahiko) ones, it is not clear if they're refering to one or to both.

On the other question, the quality of synthetic indigo if compared to the "quality measurement" of natural indigo, I'm inclined to think that synthetic indigo must be top quality since it's pure, but I don't know in what they're basing the "quality".

[jdavis]

Synthetic indigo exists as a powder. To transform synthetic indigo into dye-form it must be reduced in a vat like any natural species. In this way, the properties of the reducing agents used can affect the outcome of the synthetic indigo dye in the same way that they can affect the quality of a natural indigo.

A synthetic indigo that is reduced with enzymes and pure water would be an example of a top-notch pure (synthetic) indigo. An indigo vat with a high sulphur content would be considerably less pure.

Unfortunately, or perhaps even fortunately - as a far as indigo dye is concerned - there's a lot of grey area. Many cultures consider it an art form, and I'm inclined to agree with them. There's great variety and possibility!

[Geowu]

- a little off-topic, but I've found an interesting article about the environmental side-effects of pre-distressed jeans. It also shows interesting production steps. -

http://www.maquilasolidarity.org/resources/maquilas/journeyofjean.htm

quotes: - Manual labour - and lots of it - is required to produce the desired vintage look... and, as a result, much of the finishing takes place in countries where the labour is cheap and the dollar is strong. If kids knew the impact of their fashion statement on workers and the environment, they would realize toxic jeans are very unfashionable.

[jdavis]

Whenever I read articles like that I think of the admirable Loomstate ‘Sustainability is the way forward’ mission... and then I remind myself that they too distress and use resins...

But seriously, most of our manufacturing industry seems at odds with the environment. From the denim we wear to the packaging of our food, to our lights and air conditioners. A National Geographic from a few issues ago had a very good special on clean and sustainable energy. What stuck with me from reading it was a picture of a miner sitting on mound of coal and holding a light in his hand. Supposedly, the coal was the amount needed to power the light for the standard life of an average bulb. It was quite the reality check …

[eastcoastrider27]

I feel like everything I do is bad for the environment.

Kind of sucks.

Prefiero morir de pie que vivir siempre arrodillado

[Geowu]

jdavis, do you remember when I asked you about Tyrian Purple, the indigo color used by the Roman emperors?...

http://www.modernmicroscopy.com/main.asp?article=28&page=1

If I understood correctly, it says that, although it has been synthesized, the price for the chemicals is still very high, so it is not used for clothes, albeit being superior to blue indigo. Anymore info?

[jdavis]

I remember Geowu - you also found an article on the colonial indigo trade.

‘Tyrian Purple’ = DI (two) BROMO (bromine) INDIGOTIN (indigo)

Animal dyes can certainly be difficult to harvest, as in the case of Cochineal and Mollusk dyes. Both are ancient animal dye sources with an extremely low yield. Cochineal a scarlet insect-derivative, and ‘Tyrian Purple’ a brominated-indigo. Add to the mix tannins for brown and you have basic colour palette – Red, Blue, Brown and of course ‘Natural’ – obtained from using a resist paste on the area to be left undyed. In this way I find early textiling fascinating, as so much was done – and with seemingly little thought to how much time it would take to finish. I’ve heard of examples such as a veil that would take an entire year to complete, woven to 500s with hand-spun cotton… and then meticulously died with the indigo harvested from thousands of small shells. Fit for an Emperor indeed!

I haven’t heard of Tyrian Purple being synthesized on a commercial scale either, although I have to admit it would be an interesting and surely expensive project. Sadly, I doubt I’d be able to afford the finished product! However, that might not necessarily be a bad thing, as a jean dyed with Tyrian Puple wouldn’t necessarily fade as nicely as a true indigo pair – by virtue of Tyrian Purple being more colourfast. Perhaps in this way the humble indigo is truly superiour to its brominated cousin. Indigo fades beautifully – that’s one of the reasons we’re all so taken by it.

Another good article again – one of the better articles of Tyrian Purple that I’ve seen -

when I get back from my vacation I hope you’ll have more ready!