Archive for February, 2011

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…