Posts Tagged ‘sustainability’

Sap green

July 10, 2011

I’ve been neglecting the blog, because I’ve been insanely busy with getting my portfolio together, building my site, etc. But I’ve been experimenting with this and that as I’ve had time. Some of my recent adventures: an anthocyanin blue from geranium blossoms; an iron weld lake; shopping for a dragon’s blood tree; studying carmine in the wild; the first really successful madder lake from my garden plants (and figuring out how to make a dark and a light madder lake from the same batch); and the finding and purchasing of a natural-lake oil paint, from a very mainstream company, that has been out of circulation for most of a decade. I’ll share all that stuff with you, but for today I’ve prepared an article about sap green:

Sap green is a traditional color that enjoyed popularity from medieval illumination all the way through the Romantic era of watercolor painting. It is a warm, yellowish green, transparent, tending toward olive in masstone and a brighter, livelier green in tints. As an artist’s color it has been quite useful to many artists, filling in a difficult mixing area of the color wheel, supplying beautiful and interesting transparent green shadows, and lovely mixtures for foliage. It is fugitive, of course, like most natural organic colors, which is why it fell from vogue in the nineteenth and twentieth centuries, when modern synthetic greens that were more lightfast became widely available.

The color sap green is derived from the berries of the buckthorn plant. The usual plant used was rhamnus cathartica, or common buckthorn, which is found in the British Isles. The cathartica part of the species name refers to the fact that the buckthorn berries can be used as an emetic, and the plant is often mentioned in older medicinal treatises.

Sap Green - © MFA Boston

Sap Green - © MFA Boston

The dyestuff in Northern Europe is common and economical, and yields a beautiful color – small wonder it was popular for so long. The plant has been naturalized in parts of North America, and has become quite a problem in those areas, because common buckthorn can be very invasive. It spreads rapidly and aggressively, has no natural enemies on this continent, and quickly takes over an area of woodland, squeezing out the natural flora, and in the process some of the natural fauna as well, as they lose their traditional food sources to the invader. My original excitement to try growing this plant was dampened considerably upon learning of the problems associated with it.

I’m quite a fanatic about natural colors, of course; so, while I am an adamantly against risking introducing an invasive species into the ecolocality in which I live, I nevertheless spent some time in negotiations with myself. The common buckthorn is invasive in much cooler and wetter areas than southern Californa; there is little way the plant could be as successful here. In any case, the plant reproduces sexually and needs both a male and a female plant to spread; I’ll just get one plant, I reasoned, and so I’ll be safe. But in the end, I decided sadly that it just wasn’t worth the risks. I want to grow plants that can have a future in my garden and others – common buckthorn clearly doesn’t fit the mold, at least not on this continent. (The closest thing I have to an invasive species is madder, which is spreads agressively through root runners. But madder I feel confident I can control by killing it off if necessary, mainly because the birds and other animals of the area are not interested in its berries or seeds, so the chances of it spreading without my knowledge are greatly reduced. Common buckthorn does not have that element of safety; its berries are enjoyed and spread by many varieties of bird.)

If you happen to live in an area that has been invaded by common buckthorn, you have every opportunity to make some real sap green; for goodness sake go out and pick some berries. Every berry you use is one that cannot spread the species further.

There is another, non-invasive species of buckthorn that is actually much better suited for the hot and dry weather of California, being from the Mediterranean area of the Old World: rhamnus infectoria (or rhamnus saxatilis), the same buckthorn that is used to make stil de grain yellow lake. While a green can be made from the berries of this plant (depending on how ripe they are), it is much better used as a source of the lovely yellow stil-de-grain. You can get the berries from dye shops. I’ve been thinking of getting some seeds and growing a shrub in my garden plot; unfortunately, they seem a bit difficult to come by.

This is one of several posts I’ll make concerning the importance of localism in thinking about the sustainability of artist’s colors. If I lived in Northern Europe, sap green would be a primary color on my watercolor palette. Here in the American Southwest, it can’t be.


Which white?

February 14, 2011

The topic of sustainability has come up here (and hopefully will some more). Which artist’s colorants are more sustainable, and which are less? My thinking on this has changed quite a bit from the early days of my explorations, and turned decidedly unconventional. I now think primarily of which materials depend upon modern industry, and which do not. For instance, consider titanium white. Between lead white and titanium white, two of the few bright white pigments available to the oil painter, titanium white would probably be considered by most to the be more sustainable than the very toxic lead white. Titanium white is completely non-toxic: one of the things it is commonly used for is toothpaste – another is cake frosting. Yet I have chosen to use mostly lead white in my work. Why?

Let’s take a look at titanium oxide for a moment. Known as titanium white, this pigment is really titanium dioxide. It is generally referred to as a natural pigment, because it is found in nature in prodigious quantities in ores such as ilmenite and anatase. However, a little digging reveals that this “natural” pigment was not in widespread use, nor as far as I can tell any use at all, until the twentieth century. Why not? If it’s such an abundant, natural material – and non-toxic to boot – then it should have a much longer tradition of use, right?

Well, it turns out that this “natural” pigment requires a rather complex and energy-gobbling process to capture and purify. Yes, there is plenty of the titanium ores around – but to get the stuff into a usable bright white pigment requires extensive facilities and power. Even though the oxide of titanium was discovered and observed in the late eighteenth century, this pigment was not capable of being manufactured before the 1920s, when a hydrocarbon-driven modern industrial process finally got it done. And unless I am mistaken, that is the only way to do it on a reasonably productive scale.

(Many, many sources list this pigment, without any further explanation, as natural – including the Natural Products Association, which sets standards for “naturalness” in personal care products. I wrote an E-mail to the Natural Products Association, asking them about their inclusion of titanium dioxide, and whether it can truly be considered a natural material after the complex, modern industrial processes to which it must be subjected. I received back a very nice form letter with a little blurb describing what titanium white is, which I already knew (which should have been clear from the E-mail I sent), and which answered my question not at all. A subsequent attempt went unanswered. Now, I don’t really care any longer whether a pigment is “natural” or not – but really, in light of that response and other discussions, I have wondered if folks are perhaps a little unwilling to question titanium white too closely – just because it’s so mind-bogglingly useful. Believe me, I was more than a bit disappointed myself when I started learning about this stuff.)

Lead white, on the other hand: now this pigment does not require modern industry for its manufacture. How do I know? Because it has the track record to prove it. Lead white has been made and used for thousands of years, demonstrating it quite handily. And this is one of the main things I ask about an art material: has it proven its non-reliance on petroleum? As a general thing, I believe that if a material was commonly made and used before hydrocarbons, then it will still have the possibility to be made and used after hydrocarbons. (There are one or two major exceptions to this rule, to be discussed later.)

So, asked in shorthand:

  1. Which of these two white pigments – lead, or titanium – requires a hydrocarbon-driven industry for its manufacture?
  2. Is our hydrocarbon-driven industry sustainable?

Personally, I answer these two questions: 1., titanium; and 2., no.

Now, I admit: it doesn’t hurt that lead white is also one of the most beautiful colors in oil I’ve ever had the pleasure to apply to canvas. Really, it’s just a wonder to paint with. But that’s not the main reason I use it. I actually resisted the switch to lead white mightily at first, because I just didn’t want something that toxic on my palette. But I did believe it would more closely fit my philosophy, and so I made the switch. Haven’t regretted it once.

Iris rhizomes

Still got a ton of these, as told in the previous post. I’m giving them away to friends and neighbors at this point. About another week and they’ll be gone. Let me know if you want some…

What is a sustainable color?

January 30, 2011

Or: the good, the bad, and the ugly

Despite more than a bit of misuse in popular culture, what the word “sustainable” actually means is simple – though the implications are quite profound for us all – and it’s this (from

  1. : capable of being sustained
  2. a : of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged
    b : of or relating to a lifestyle involving the use of sustainable methods

So here’s my interpretation for the purposes of this discussion (and my own philosophy):

An activity is sustainable if it in no way impedes the ability of future generations to live their lives or to engage in the same activity or other activities – for all intents and purposes forever.

If an activity does not meet that test, then it is unsustainable. Can’t keep it up forever. Can’t sustain the activity indefinitely. If you try to keep up that activity forever, then eventually you crash. It’s a fail.

Sustainability is not a nicety. It’s a requirement and a hard fact. If an activity is unsustainable, then that means we will stop doing it – eventually. The only question is whether we cease the activity voluntarily, or are forced out of it through diminishing options – or whether we ourselves will meet our end before it becomes an issue. (As one cynic put it: We will keep doing what we do until we can’t any more, and then we won’t.)

So that’s my strict definition. But “forever” is a little hard for the human brain (at least my human brain) to comprehend and plan for. When I think about this stuff, I tend to think in more discrete chunks of time, because it’s easier for me, and it clarifies my thinking: five thousand years from now, ten thousand. Will our heavy industry still be consuming at its present rate in ten thousand years? Will the Three Gorges Dam still be standing? Will we still be mining for cobalt?

This, of course, is a blog about art materials, and more than anything else it’s about colors. So which colors are sustainable? Which are not? Which are finite, but nevertheless are abundant enough to probably last the long millenia?

The good

These are the materials that really could last pretty much until the end of the world. Non-destructive, renewable, natural organic colors (definition here) that can be raised or wildcrafted in one’s own bioregion (geographic backyard), and can replenish themselves, through careful horticulture or natural propagation, and can be prepared over a simple fire using abundant, locally available ingredients – these are probably the only colors that can be considered truly sustainable by our strict definition above. One can conceivably at least keep up that activity pretty much forever, so it does pass that test, assuming it’s done with care. (However, it should definitely be noted here that not all natural organic sources pass the test. More on that in the next post.)

Also, I think we can go a little easy on ourselves here and throw the natural earths into this category. Although technically they are finite (especially the nice brightly-colored ones), well, there’s just a heck of a lot of the stuff out there. It’s a little hard to imagine artists ever managing to use up all the red earth in Arizona – or Brazil.

The bad

The pigments that are most clearly unsustainable, for various reasons that should be fairly obvious, are the ones that are manufactured from petroleum or other hydrocarbons. These synthetic organics (definition here) are going to go away sooner or later – more likely sooner. For me this is the most easily identifiable group. Flatly not sustainable, because petroleum isn’t. End of story. I’ll actually be rather surprised if they manage to still be around for much longer than another decade or two.

Perhaps slightly less obvious are the pigments that merely require a hydrocarbon-driven industrial process for their manufacture. They may not have petroleum as their basic feedstock, but they are just as dependent upon it for their existence. I don’t see how this group can make it out of the cellar either. I’ll be going through a few examples in later articles.

The ugly

Any material which is finite is therefore, strictly speaking, unsustainable. However, common sense and a little research indicate that there are certain natural inorganic materials that are so plentiful (and in some cases highly recyclable as well) that we probably don’t really need to worry about them, at least not for a very, very long time. Iron and alum in particular, which can be used to make Mars pigments and lake pigments, will almost certainly not deplete completely from the major regions of the earth in any time scale meaningful to this discussion. Also, the minerals calcium, sodium, potassium and sulfur – also used in the creation of lake pigments and some other pigments – are in abundant supply as well. There are a few other materials that I also count as reasonable candidates for this group, depending on other factors.

So, luckily, I doubt we will ever be restricted to using natural inks and earths only, even though they’re the only materials that actually made it into our “good” category. (As much as I love natural inks, I do like to make an oil painting once in a while.) We’ll be collecting earths, and making lake pigments and a few synthetic inorganic pigments (definition here), for a long, long time to come.

Forever? Can’t answer that. Ten thousand years from now? Almost certainly.

Details to follow…

Non-toxic pigments

August 22, 2010

I’ve engaged in a couple of online discussions lately concerning non-toxic pigments. I have a slightly different take on toxic pigments than might be usual, though I do think it’s a topic worth exploring. First, many people who care about environmental issues seem to equate “non-toxic” with “sustainable.” I think this is far from the truth, or at least far from a useful definition, and can possibly indicate a certain laziness in how we’re using the word “sustainable.” I’m certain I’ll talk about that word and what it means more later on, but it is a complex subject which nevertheless has a fairly straightforward definition. Here are the first two definitions given by

  1. capable of being sustained
  2. … capable of being maintained at a steady level without exhausting natural resources or causing severe ecological damage …

… Nowhere is toxicity mentioned. I think people may have the idea that if a substance is toxic, then it must be less healthy for ecosystems, and is therefore less sustainable – but that’s only partly true. Take copper, for instance. Copper-based pigments are considered somewhat toxic; and it’s certainly true that if a large amount of copper substance is dumped into, say, a wetland or river, it can wreak havoc with those systems. However, in a larger sphere: copper is a very abundant material in nature – it’s all over the place – and in addition, it’s highly recyclable, and is even a necessary trace element for human health. So: sustainable? Who knows? – it would take a pretty in-depth study to arrive at any reasonably solid conclusion.

On the other hand, what about pigments that are derived from petroleum feedstock, the synthetic organics? Some of those aren’t considered directly toxic, and yet consider their source. When it comes to ecological systems – and, incidentally, human health – hydrocarbons are overall the most toxic substance I can think of. That’s more the way I tend to think of it: what is the toxicity of a material – but all the way through its extraction, manufacture, processing, use and disposal? If you approach it that way, nothing can really compare with petroleum and coal.

However: the more direct toxicity of art materials can be considered ecologically important, at least in a local sense, if one is concerned about the disposal of waste from those pigments – brush water, paint-soaked rags, residue in brush-cleaning jars, etc. One poster brought up this subject at the AMIEN forum, since he was planning to travel to the bush in Costa Rica, and wanted to know which pigments might be of least ecological concern when it came to dumping his brush water out in the wild. An interesting question.

The folks at AMIEN have a different view of the topic than I do: they recommend treating all art materials as if they were toxic, and dislike to use the term “non-toxic” at all, since it is an unregulated term. On the other hand, they also suggested that whatever tiny amounts of toxic pigments were present in brush water wouldn’t be enough to worry about – and if one were really concerned about it, she could simply pack an extra bottle to pack out the used brush water. However, when I go camping, I tend to think just the way the original poster did, and only bring those pigments that I feel will be absolutely harmless to whatever area I’m visiting. After all, it is someone’s home.

For those of you who don’t camp, what about the same policy at your home? Do you dump your cadmium brush water down the drain? Should you? Stuff to think about…

The AMIEN folks brought up an interesting point: if you’re talking about commercial paints, you may feel okay about a particular pigment the paint contains, but who knows what other ingredients may be in the paint – fungicides, preservatives, etc. – but not indicated on the label? Yet another reason to make one’s own paint…

Incidentally, if you’re interested in topics concerning art materials but are not yet familiar with the AMIEN forum, you might go ahead and get acquainted. I love that site, I visit it almost daily, and as someone who is interested in art materials I find the information and help there to be extremely useful. (I’m going to go ahead and include a link to the AMIEN [Art Materials Information and Education Network] site on this blog. Look to the link list!)

Van ink drawing

Van ink drawing

More on non-toxic pigments in the next post, including a review of another recent online discussion on the topic. In the meantime, some stuff going on with me: I had intended to post today about my next piambura underpainting, but unfortunately I screwed it up badly. So I won’t. I’ve also put my very first piece of art up for sale on Ebay (the auction is now over – didn’t sell), and have now put the item up for sales of reproductions on Redbubble and ImageKind. It’s an ink drawing made with a quite ordinary ink – acrylic-based – and so isn’t really of interest to the topic of this blog. But since this is currently my only blog, and my very first posting for sale is something of a momentous event for me, I’m posting the pic to the right. At some point I’ll begin another blog just for my artwork. ‘Till next time!