crazyboy - 23-9-2019 at 22:03
Hey, it's been a while. Not sure if anyone remembers me. I'm working on lichen dyeing, a number of lichens contain orcein which produces a range of
purple and red dyes. https://en.wikipedia.org/wiki/Orcein
Most information on the subject is not very technical but it boils down to soaking the orcein containing lichen in ammonia and aerating it by shaking
for weeks on end before using the resulting liquid to dye textiles.
I'm trying to do this faster and more intelligently. I did find this article: https://sci-hub.tw/10.1016/j.microc.2018.01.033 whcih mentions the use of EDTA. But not much info on the overall chemistry and alternative
approaches. Any thoughts?
Metacelsus - 24-9-2019 at 03:56
That paper seems to be about extracting the dye from yarn (which presumably contains metal salts as a mordant, hence the EDTA). However, you want to
extract it from lichen. Besides extraction, air oxidation is necessary to produce orcein. This is why the aerating and shaking is used.
This page has some info: https://web.archive.org/web/20181119001849/http://www.anbg.g...
And also see this old book: https://books.google.com/books?id=xj9AAQAAMAAJ&pg=RA3-PA...
UC235 - 24-9-2019 at 14:48
I actually have 3 jars going right now, attempting to produce litmus. I'm using smooth rock tripe, Umbilicaria mammulata.
There is little to no clear details on producing litmus/orcein. I rather expect everyone kept it a trade secret though there are vague details about
mixing with ammonia, lime, potash, and possibly gypsum.
I put 33g of dried, crushed lichen into a 1qt mason jar, and added 400ml of 2.5% ammonia. It may have been better to go stronger, but online recipes I
found for making lichen dye called for half strength "household ammonia" which is usually around 5%. I left one jar with just ammonia.To one jar, I
added enough NaOH to make it 0.1M. To the third, I added 0.1M sodium carbonate and enough calcium hydroxide to convert it to NaOH. I figured this was
what the mix of lime and potash was meant to do.
I put on lids and have been opening ocassionally and shaking for the last 4 months. A dark red brown color develops in the first few days. This gets
darker and now, months later with a fair amount of neglect in a hot garage is shifting to deep purple, indicating the presence of blue chromophores.
Interestingly, the carbonate/lime/ammonia jar seems to be progressing the slowest of all three. The NaOH/ammonia is developing slightly faster than
the ammonia only jar.
crazyboy - 24-9-2019 at 22:57
Nice UC235! I also have three jars at the moment. What a coincidence. I have Umbilicaria phaea, a mystery Parmeliaceae, and Peltigera membranacea. All
are soaking in 5% ammonia solution. I'm following "Lichen Dyes The New Source Book" and https://www.fungimag.com/summer-2014-articles/LR2%20V7I2%2066-69%20Dies.pdf
Just dyed a silk handkerchief with Letharia Vulpinia, not as saturated as I would like. Just bought some wool yarn to test.