Exciting Lichen Information!

After all the flax-related posts lately, you might be justified in thinking that I don’t care about dye plants anymore. Not true! I thought I’d kick off what I hope will be a series of posts about dye plants with a link to a fascinating article about recent research on lichen.

OK, technically a lichen isn’t a plant. What exactly is it? Well, I used to think that a lichen was a symbiotic organism composed of a fungus and an algae (perhaps more accurately, “alga” singular). My go-to definition is from Lichens of North America by Irwin M. Brodo, Sylvia Duran Sharnoff, and Stephen Sharnoff. This massive and beautiful book is one of my prized possessions, acquired from Raven Used Books in Northampton many years ago (FYI my beloved Matthew is a former employee and does their website, as well as websites for many other good folk). I abbreviate the definition here:

“[A] lichen is not a single entity, but a composite of a fungus and an organism capable of producing food by photosynthesis. Lichen fungi can associate with green algae or cyanobacteria (the latter also known as blue-green algae), or sometimes both […]. The special biological relationship found in lichens is called symbiosis.”

The authors also offer a sweet, almost diminutive term for the photosynthetic symbiont, “photobiont, for short,” which is a word I aspire to slip into casual conversation more often. (Well, OK, ever!)

However, please follow this link for some exciting new insights into the life of lichen ….


Madder and Flavoparmelia Dyebaths

After three extractions and a lot of soaking in between, my madder and lichen baths are ready to go. I’m sticking with Flavoparmelia caperata for the ID on the bark-growing foliose lichen, though I’m sure I could be wrong.

For each dyebath, I combined all three extractions. Next for some tinkering.

Here are the color and pH of the madder bath before I did anything to it. Brown.

initial madder bath colorinitial madder pHI would call that pH6 which is acidic, not where I want it to be to develop good reds. So, first I added more calcium carbonate (there was already one teaspoon in the roots as I extracted them). This did not produce much of a pH shift (see below). I’d still call that 6, though I don’t know what’s up with that bottom square. It’s not supposed to be so orange. Happily, the color darkened and shifted a little from brown to red.

madder bath color with chalkmadder bath pH with chalkI wanted to get the pH up a little, so I added 1/2 teaspoon dissolved soda ash at first, which got it up to pH 8 (photo on the left below). The dyepot contains about 2 gallons of liquid. I did not weigh my modifiers or figure out the percent on the weight of the dyestuff this time around (I extracted 8 ounces of roots). After another half teaspoon of dissolved soda ash, the pH was 9, which I was happy with (photo on right).

madder bath pH with half teaspoon soda ashmadder bath pH with 1 teaspoon soda ash





Since I’m dyeing linen, I’m not worried about making it too alkaline. I introduced a 2 ounce skein of 20/2 linen half bleach, which I had mordanted with alum acetate back in December, and re-mordanted yesterday for good measure. After 30 minutes heating, the color was promising:

linen yarn in madder bath at 30 minutesHere is what it looked like once I got up to my target, and maximum, temperature of 160 degrees (over 160 you’ll get brown rather than red tones):

linen yarn in madder bath at 160 degreesI am very satisfied with this so far. My quest to create rich color on linen yarns seems to be advancing, though I shouldn’t speak too soon. The color is always lighter once it is dried and rinsed. I held the temp between 150 and 160 for an hour (and actually had to shut off the heat for a while to keep it from getting too hot). Next, the skein will sit and soak all day and overnight in the dyebath, and then it’ll drip dry before I rinse it. I find that delaying the rinse helps with fastness. So, that’s the status of the madder bath. As the week progresses, I expect to re-use the bath repeatedly and get a lot of pink, salmon, apricot, and so on until it’s exhausted.

The Flavoparmelia experiment is less exciting, but at least now I know not to bother with it again, so that’s useful information anyway. Here’s the initial color of the dyebath with all three extractions combined (I started with 5.4 ounces of lichens including a lot of bark).

initial color of Flavorparmelia bathThe pH was a bit weird. I didn’t take a photo (by now you’re probably tired of photos of pH strips). It looked like 6 at first, but as the liquid wicked up it shifted to 5. The initial color of the skein was light and not promising.

linen yarn in Flavoparmelia bath at 30 minutes pH 5Just for the heck of it I decided to see if the color was pH sensitive (since I already had the soda ash out anyway…). I put some of the hot dyebath liquid in a jar and added 1/4 teaspoon of soda ash. It darkened, so I decided to add this solution to the dyebath (I took out the skein first). Since this dyebath contains less liquid than the madder pot, about one gallon rather than two, even such a little soda ash had a noticeable effect on the pH, which went up to 8.

Flavorparmelia plus quarter teaspoon soda ashlinen yarn in Flavoparmelia dyebathlinen yarn in Flavoparmelia bath after 8 hours




OK, I guess there isn’t a big difference between these two photos. On the left is the yarn halfway through heating it, and on the right is how it looks after sitting and soaking for eight hours. I do not plan to exhaust this bath.

New Umbilicate Vats

Last Friday (February 24th) I set up three new umbilicate lichen vats with the fallen lichens I collected on February 1st and 6th. I had stored them in two different bags. The material in one bag was damp, and the other dry and crispy. You’re supposed to dry them first, but I proceeded with the damp ones and hope it works out.

Several of the pieces were enormous. If they grow half a millimeter a year, this six inch piece must have taken over 300 years to reach this size!

six inch lichen pieceThis piece, too, must be ancient.

four inch lichen pieceAs you can imagine, handling these things inspires awe.

I crumbled up the dry ones, tore the damp ones into small pieces, and combined them. I had 12 cups all together, though “cups” is sort of relative because you can compact them, and then they spring back up again. The total weight was 12 ounces. I divided the lichen pieces between three jars, with 4 ounces in each.

lichen on scaleWith the exception of using the damp lichen, I followed the directions in Casselman’s Lichen Dyes. I also found and re-read her article “Color Magic from Lichen Dyebaths” in Shuttle, Spindle, and Dyepot from Spring 1986 (vol. 17 #2), which I forgot to mention in my posts before.

She says to choose a jar that can accommodate twice the volume of the lichens. You need a lot of headroom in the jars to allow the lichens to expand when they get wet, and to make sure there is enough oxygen in the vat. I put the crumbled up lichen in the jars, and added equal amounts of ammonia and water (2 cups of each). The ammonia solution was pH 10.

lichen vat pHHere are the jars.

new lichen jarsYou can see that the bubbles on the surface are clear (well, a very light color).

After a week of stirring up the soaking lichens each day to incorporate oxygen, the color is developing nicely. Here’s the spoon I’ve been using, plus some of the liquid which has dribbled off.

lichen vat stirring spoonHere are the jars after a vigorous shake this morning. Note the darker, more reddish-colored bubbles. I have to admit that I have not been stirring as many times a day as Casselman recommends, but things seem to be moving along OK.

lichen vats after 7daysIt takes at least 16 weeks for an ammonia vat to develop and “ferment” properly. I will continue to incorporate oxygen regularly, which Casselman says is necessary to allow the orcinol to convert to orcein. So, don’t hold your breath as I probably won’t post about these vats again until June.

February 29th, 2012

The Leap Day of the Leap Year

leap year snow Today it is snowing. A much more typical wintry day than February 1st. Here’s what I have been doing so far today, fiber-wise:

I wove a section on my new warp, threaded once again with Young Lovers Knot, for a new batch of journals. Today I wove the section in the photo below. The blue is 22/2 cottolin dyed with woad and weld, and the tabby weft is teal 20/2 cotton, commercially dyed. When I first dyed the cottolin I was disappointed not to get a better green, but with the brighter colored tabby background it looks very nice anyway.

woad and weld dyed cottolinI changed the treadling for the sections where I’m using 20/2 linen or 22/2 cottolin because no matter what I do, I can’t beat it square with these yarns. With 10/2 cotton or 10/2 tencel it’s not a problem. Linen is just less inclined to submit to compression. It’s one of the things I love about linen, it has a mind of its own. And really, it’s not meant for overshot pattern weft, so who can blame it? To accommodate the linen, I shortened the square (or table) by two picks.

I wet-spun spun some bleached flax top (from Louet, not my own). It’s tow (short fibers). I did about half this bobbin today. My legs got wet, but it went with the snowy theme outdoors, so I didn’t really mind.

wet spun towI was originally planning to spin a second bobbin and ply them, but I think I will leave it as singles and take out some of the extra twist when I wind it onto bobbins for weaving. My new plan is to spin the other half dry and then weave samples with them (using them for weft) to see if there is a noticeable difference between wet and dry spun tow.

I did the second extraction on two new dyebaths that I started over the weekend. One is madder (8 oz. roots bought from Aurora Silk a few years ago). The other is the Flavoparmelia lichens I collected this winter, plus the bark they were growing on. Since it is snowing, I heated these indoors today. Fortunately, they both smell amazing. Too bad you can’t smell them. The lichen smells like hot piney woods in the summer or a toasty fire in a cabin in the woods. The madder smells fruity, like red wine or blackberries getting boiled for jelly.

flavoparmelia dyebathmadder dyebathI plan to extract each one more time, then combine the extractions for stronger color. With the combined extractions, I am hoping to get a respectably rich color from the first madder bath, at least. The Flavoparmelia is an experiment, but I figure I’ll give it every opportunity to yield a strong color, if it can.

I am sticking with cellulose yarns for the time being, which are proving to be tricky. The colors are coming out lighter than I expect each time, with the exception of the CRAZY bright weld earlier in the fall/winter. Here’s how it’s looking woven up. These two photos show 20/2 linen half-bleach pattern weft with black 20/2 cotton tabby (on the black warp).

weld dyed linenweld after woadThese two show the same weld-dyed yarn with a light blue 20/2 cotton tabby weft. It’s a very woady blue, but it’s commercial. (In these sections I had not yet shortened the square, hence it is rectangular.)

weld with blue tabbyweld with blue tabby closeupLast but not least, I have stirred up my new umbilicate lichen vats to incorporate oxygen. I will post about that separately.

It’s been great to have an extra day to work on all these projects. We should have a leap day every year.



What’s a Lichen?

What is a lichen, anyway? A lichen is a symbiotic organism composed of a fungus and another organism that can photosynthesize. Fungi do not photosynthesize, that is, they do not make their own food from sunlight (and carbon dioxide and water) using chlorophyll. They are heterotrophic, meaning they get their nutrition from outside themselves. Fungi are different from plants and have their own taxonomic kingdom. The photosynthesizing organisms in lichens are different kinds of algae, cyanobacteria, or sometimes both. The photosynthesizing part of a lichen is called the “photobiont” (short for photosynthetic symbiont).

The photobiont makes sugars and other carbohydrates through photosynthesis, and allows some of these nutrients to be absorbed by the fungus. In return, the fungus provides structure and stability, some protection from sunlight, and as much consistent moisture as the habitat can provide, by conducting water through its cell walls. The fungus combined with its photobiont grows into a particular shape or structure. By itself, with identical genetic information, the fungus would not grow into this shape. The algae and cyanobacteria would not be able to colonize rocks or bark or other places that lichens grow without the fungi.

Lichens are amazingly complex, and scientists still don’t know all the details about exactly how they work. They come in a huge range of colors, textures, shapes, and sizes, and grow on lots of different surfaces (or substrates) in a very wide range of habitats. Some lichens are able to fix atmospheric nitrogen, and play a role in creating conditions to support plant life. Lichens readily accumulate minerals, including toxic compounds, are thus very susceptible to pollution. They grow very slowly. Foliose lichens (named for their leaf-like structure) like my Flavoparmelia caperata grow an average of .4-.5 mm a year. Umbilicates are also a type of foliose lichen with extra-big “leaves.” Umbilicate lichens form new cells at the center, which is why it doesn’t kill the lichen to tear off small pieces from the outside edge.

The acids and other compounds that make lichens useful for dyers serve a range of functions in the lichens themselves. Some are pigments that filter out certain wavelengths of light, some have antibiotic properties that inhibit other organisms that might compete with the slow-growing lichens, some make them taste bad so herbivores won’t eat them….

OK, I could go on and on, but if you’re interested you can read more on your own. Again, here are my two trusty references:

Lichen Dyes: The New Source Book by Karen Diadick Casselman. Mineola, NY: Dover Publications, 2001.

Lichens of North America by Irwin M. Brodo, Sylvia Duran Sharnoff, and Stephen Sharnoff. New Haven: Yale University Press, 2001. This is THE book. In addition to being an incredible and beautiful reference, its bulk makes it useful as a book-binding press, and occasionally to hold up the printer:

lichen book holding up printer

A Tale of Lichen and Weird Winter Weather (Part Six)

This part of the story actually happens before the lye testing in Part Five, but to me it is the climax of the whole story, so I saved it until the end.

As the ground stayed bare this winter, I continued to see lots more (probably) Flavoparmelia caperata lying on the ground, and other lichens. It made me wonder how much usually gets buried under the snow. Does it usually get crushed and decompose? If it had been a regular snowy winter, I’d never even know it was there. Which leads me to….

Part Six: Non-Snowy Woods on the First of February

The first of February was glorious and warm and sunny. To celebrate the day, I went for a longer walk than usual. A hike. There was not a patch of snow on the ground anywhere, only occasional ice. Just as I was thinking about how happy I was that this non-snowy winter enabled me to learn more about lichens, I noticed a lot of umbilicates growing on a rock face that I’d never really noticed before. I scrabbled over to check at the base of the rocks for any fallen pieces. There was an incredible, astonishing abundance! I felt like I was in a fairy tale; I’d been thinking about how awesome lichens are, and then ta-da there were tons of them. Magic. And not just any lichens, the awesomest ones.

I filled both my pockets with loose pieces from the ground, but there was way more than my pockets could hold. A blissful day and a blissful foraging treat.

Here are some photos. Some pieces were right on the ground, and some were hidden under the leaves. The underside of these umbilicates is velvety and black. The top is greenish, olive, or brownish. They are sometimes called “rock tripe,” hence the labels on the photos (if you hover over or click on an image it tells you the title of the photo).

fallen rock tripe black undersidedamp fallen rock tripefallen rock tripe underneathdry fallen rock tripeI went back to the same spot on February 6th (another glorious day) with a gallon sized zip lock bag, and filled that also.

The discovery of this abundance made me wonder whether this much falls off every winter, or whether more pieces than usual broke off this year because of the weird (comparatively warm and dry) weather. Would I find this much again another winter? I’m not sure, but I don’t think so. I think this weird winter was special.

A Tale of Lichen and Weird Winter Weather (Part Five)

Part Five: Picking up Fallen Lichen in the Non-Snowy Woods

Right after the big storm in October, we had a spell of very warm weather and all the snow melted at the beginning of November. However, the broken trees and branches still lay everywhere. Lichen and salvage botany were very much still on my mind. Karen Diadick Casselman wrote in Lichen Dyes that in the woods behind her house, several species of lichen dropped daily to the ground, which provided an almost unlimited supply, should she choose to use them. (She went on to say that she focuses on studying lichens rather than on dyeing in volume.) I wondered how much lichen could be gathered if I picked up only what had fallen on the trail, road, or sidewalk as I went on my walks, and only what was most abundant. Well, in one week of walking almost every day, I had 4 cups of this lovely stuff (including quite a lot of bark, to which it was attached):

lichen on groundlichen on oak barkTo be honest, I’m not positive it was all the same species, but visually all the little pieces looked very similar. I could sure collect a lot of it, but what exactly was it, and was it useful for dyeing?

Positively identifying it has been an on-going process. Today I completed the most recent step, having acquired a container of lye from my mom, whom I visited yesterday. Thanks, Mummy!

Earlier in the winter, I had gone through the dichotomous key for “foliose lichens that are not umbilicate, jelly-like, or yellow” in Lichens of North America. With a pretty good degree of confidence I continued on to the Parmelia key. The most likely candidates were Flavoparmelia caperata (a.k.a. Pseudoparmelia caperata, the Common Greenshield lichen), Flavopunctelia soredica, or Flavopunctelia flaventior. The time had come for chemical testing.

I hoped that using just bleach for the C test (short for calcium hypochlorite), I could tell the difference between F. caperata and F. soredica or F. flaventior. Here’s why. Both of the latter are supposed to react C+ red when spot tested on the medulla. That means when you scrape off the top layer (cortex) and expose the white layer underneath (medulla), then apply a dab of bleach to the white area, it will turn red. It didn’t. Here’s a photo comparing the foliose lichen in question with an umbilicate lichen that definitely did react C+ red.

comparing the color of C+ and C- reactions on lichenThe umbilicate is in the lower part of the photo, and shows a very bright red-orange reaction. The foliose lichen above shows very little color change. Depending on how dramatic the reaction is supposed to be, you could call it yellow, or you could call it nothing. On the medulla of the foliose lichen, there was more of a reaction (the spot on the upper right which is a little bit darker yellow), but it’s definitely not red.

Having ruled out F. soredica or F. flaventior, I was pretty happy to say that my abundant foliose lichen was Flavoparmelia caperata. But I didn’t actually prove what is was, only what is wasn’t. Enter the lye, which lets you do the K and KC tests (K stands for the potassium in potassium hydroxide)

F. caperata is supposed to be K- on the cortex and medulla, KC + gold on the cortex, and KC+ pink on the medulla. Here’s what my results this morning looked like. The first photo shows a piece of the lichen with the medulla exposed (the white area):

foliose lichen with exposed medulla

K minus cortexThe photo above shows the K- reaction on the cortex, and the one below shows K- on both the medulla and cortex. It’s slightly brighter green where I dabbed on the lye solution because it’s wet.

K minus on the cortex and medullaThe photo below shows the KC+ reaction on both the cortex and medulla. (KC means you apply a dab of lye solution, then a dab of bleach on the same spot.) However, I would not call the color on the medulla “pink,” exactly. It’s redder than the gold on the cortex, but it’s more orange, I’d say.

KC plus on cortex and medullaOn the other hand, my “red” reaction on the umbilicate was sort of orange, too. So, there you have it. Probably my abundant foliose lichen is Flavoparmelia caperata. It does not appear to be an interesting source of dye, unfortunately. I may go ahead and try it anyway. I’ll let you know.

A Tale of Lichen and Weird Winter Weather (Part Four)

Part Four: Dyeing with the Ancient Umbilicate Vat

Winding skeins, scouring, mordanting, tannin baths, etc. took a long time, so the dyeing didn’t actually happen until December. It was the first time I’d used lichens on cellulose fibers. According to Casselman, and others, lichens are substantive dyes, meaning they don’t require a mordant. But I’m inclined to agree with Joan Morris, who said in a workshop last summer, “With natural dyes, cellulose fibers need all the help they can get.” Cotton, linen, and other plant-derived fibers are not naturally inclined to slurp up color the way wool does, so you’ve got to give the fibers every opportunity to hold onto the dye molecules. I decided to mordant with alum acetate *and* treat the yarns with a tannin bath for good measure.

Here’s the vat liquor strained into a jar, undiluted, pH 12 or 13.

umbilicate lichen liquor in jar Here in the dyepot you can see the magenta color of the vat liquor.

umbilicate lichen liquor colorI diluted the vat liquor with water (6 cups vat liquor to 28 cups water) and the pH was 9. Into this stinky (rotten fishy) pot went my tannin and alum acetate-treated linen and cottolin skeins. Well, if you read my earlier post about weld and cellulose, you know that tannin can have a darkening and weirdening effect on color, even the gallotannin I’ve been using, which is very light. The darkening effect of iron is called “saddening,” so maybe I can call it saddening with tannin, too, but it’s not quite the same. Anyway, you can probably already picture the scene. Here it is:

umbilicate lichen with tannin on celluloseYes, I got a very interesting purplish brown. Basically brown. An unusual sort of brown. But brown. At first I was disappointed and felt very bad because, to me, dyeing with lichens is a weighty thing. I feel there is karma, or at least a moral burden, attached to it in a way I do not feel with goldenrod or Queen Anne’s Lace or other more happy-go-lucky sorts of plants. Venerable ancient organisms shouldn’t be wantonly ripped up and fermented for the making of browns.

Here though, I must digress. Later in December and January, I noticed this color regularly on my walks, especially in the woods when the sunlight was orange-pink early in the morning or just before sunset. Something about the light made the trunks of certain pines (red pine, I think) reflect exactly this purplish brown. I also saw it in tangles of old blackberry canes, and where red maple leaves had fallen and dried among oak leaves. When I noticed this, I felt grateful to the lichens for having opened my eyes to this color. It’s a real color in its own right, with a place in the world, not just an accident or a mistake. Now I love that color. OK, back to the story.

Back in December, still hoping for pink, I added a little soda ash to the exhaust bath to bump the pH up to 10, and used bleached cotton skeins mordanted only with alum acetate. I got a pale bluish pink, a very subtle color, and was happy.

umbilicate lichen no tannin on cotton

A Tale of Lichen and Weird Winter Weather (Parts One, Two and Three)

This is a long story. I will tell it in parts.

Part One: The Snow Storm

At the end of October, 2011, we had a big snowstorm. The snow was wet and heavy, and snapped and broke tons of trees and branches. There were sad broken trees all over the place, and it took a very long time for all the wood to get cut and stacked or moved away. In the woods, depending on how much people-traffic there is, a lot of trees and branches are resting where they fell to this day. And many of these trees and branches were, and are, covered in lichens. It was an unusually early storm with an unusually destructive impact–the first installment of the weird winter, weather-wise.

Part Two: Karen Diadick Casselman

Around this same time, I was planning a series of cellulose dye projects. One of the dyestuffs I wanted to use was an umbilicate lichen fermentation vat that had been sitting in the closet for an indeterminate length of time. Well, it was determinate. Since July 2006. I know, ridiculous. I blame my Master Weaver certificate. After so long, I figured it was time for a refresher on lichen dyeing, so I re-read Karen Diadick Casselman’s Lichen Dyes.

It is an inspiring book on several levels. I especially appreciate her guidelines on the ethics of gathering and using lichens, and her promotion of “salvage botany.” After rereading her book, I was embarrassed to realize how far I had fallen short of the Code of Ethics she outlines, and was motivated to try harder. She suggests learning to identify five species of lichen, including the Latin names, before you collect or use any. I haven’t done this.  I’m lucky to own an incredible resource, Lichens of North America by Brodo, Sharnoff and Sharnoff (a score at Raven Used Books in Northampton many years ago), so I don’t really have an excuse. Among her other recommendations, which I do follow:

“Focus your attention only on found (unattached) lichens.”

“Use for dyeing only those lichens that are conspicuously abundant.”

“Avoid using lichens to make unexceptional dye colors (e.g., beige).”

I take to heart, in particular, this admonition and astonishing, awe-inspiring fact:

“Learn to appreciate that large umbilicate lichens may be hundreds of years old. Respect these organisms as you would any other botanical specimen of mature years.”

Part Three: A Little Personal Lichen Back-story

My first lichen experiments were in 2004. I used two different types that had fallen from the trees onto a lawn on Cape Cod. With the boiling water method and no mordant on wool (Finn), one type produced a warm creamy yellow, and the other golden brown. I never did positively identify them. The one which made yellow was possibly some type of Usnea (my best guess was Usnea strigosa), the other possibly a Flavoparmelia (F. caperata?) or Rimelia (R. reticulata?).

Here are the same samples on two different color backgrounds. The sample in the center was first dyed in the yellow bath, then the golden brown one:

lichens yellow and goldlichens gold and yellowBoth lichens yielded colors that were much better than beige, but I felt like I could get these colors in other ways, so I didn’t try them again.

Some lichens make amazing colors in the magenta, red, and pink range, with an ammonia fermentation vat. It is very hard to get these colors with natural dyes, unless you use cochineal. Cochineal is not local to New England. Plus, it’s pregnant female bugs and that just makes me feel bad. So, using these special lichens seems worthwhile to me.

These awesome lichens are called umbilicates. An umbilicate lichen attaches to its substrate (what it grows on) by an umbilicus, which is like a little foot or holdfast, or an umbilical cord. I’m sorry to say that I am still not positive if I have been using Umbilicaria americana or U. mammulata, or perhaps both (apparently they often grow together).

These umbilicates are not too hard to find, if you do a lot of hiking around in the woods. They grow on steep rock faces, and where they are happy you can sometimes find tons covering the whole surface. It’s a simultaneously earthly and alien sight.

Here are some happy lichens growing on a small south-facing cliff yesterday (February 6th, 2011):

umbilicate lichen on rock

umbilicate lichen on cliffIf you tear around the edge and leave the umbilicus attached, the lichen can keep growing. My practice had been to gather infrequently and sparingly from several different spots. This was how I gathered the jar-full that had been sitting in the closet in an ammonia solution fermenting for oh so long. I have used them a few times very successfully on wool.

Here are the samples of my umbilicate dyebaths on wool, using the ammonia fermentation method that Casselman outlines in her book.

umbilicate lichen pale pink on wool

umbilicate lichen pinks on woolThe top pictures demonstrates that too much fiber will give pale colors, so don’t be greedy with umbilicate vats. This process requires a bit of discipline and restraint.  In the bottom picture, the difference in color between the samples on the right and the ones on the left is due to pH. The ones of the left were immersed in a high pH bath (not as high as the vat itself, but still very alkaline). For the ones on the right, I added vinegar as well as water to the vat solution, and got the pH down to 7. In general, higher pH (alkaline) will give more blue colors, and lower pH (acidic) will give more reds.

There’s more to come in the lichen saga, so stay tuned.