Drat!
This post is merely an introduction to this problem and I urge you to read the entire study on the link above.
Zinc white oil color has a BIG drawback; it makes a rather brittle paint film.
Zinc whites' brittleness can cause cracks in paintings after only a few years, if it is used by itself and in excess.
Should artists toss out their tubes of white oil color containing zinc white?
The answer is YES . . . if you want your work to be archival.
The above detail of a painting by Henry Cliffe, painted in 1959, shows severe cracking and peeling (from rolling the painting) in paint containing a combination of both lead white and zinc white.
The majority of white oil paint available today includes zinc white.
Even "Titanium White" or "Flake White" may likely contain Zinc White (not always listed on the label). Ouch.
Of course, not every painting containing zinc white will crack and its paint fall off the support.
Ophelia (1852-97) by John Everett Millais has areas of zinc white priming. Remarkably, the painting is in generally good condition and does not show problems.
So why is zinc white is so commonly found in white oil paint today?
Zinc white is transparent, nontoxic, doesn't darken and offers a brilliant white allowing artists to obtain highly saturated colors.
In the past I have used Zinc White in small amounts because of its transparency and ability to "cool" an area.
Right now I am using "Titanium White" and hope it doesn't have much (unlisted) zinc in the ingredients. I use a very small amount of Titanium white in Liquin (or any medium) as a thin scumble to replace the zinc white paint I used to use.
So, if any reader knows of any high quality artist's white oil paint that does not contain lead and/or zinc, please let me know.
3 comments:
I read this article about a week after ordering a zinc white dispersion, thinking I'd like to experiment with the pigment as several of my favorite painters had been working with it. Quite a shock and lucky timing after spending a year making sure everything on my palette was rated ASTM 1.
Encouraged by a friend I contacted Dr. Mecklenburg to find out a little more. He said zinc wasn't an issue in casein or egg tempera but was a big problem with aklyds and oil... casein is wonderful for oil underpainting so for any painter who love to use zinc in a layered process this could be an option. I wondered if this is the reason for the Millais being in such good condition, as some of the pre raphelites may have used egg tempera in their work, like many of the flemish painters.
Some of the high end makes of titanium are zinc free but kamapigment whose pigments are very high quality can custom mix oil paints, and they assured me their titanium is 100 percent pure. I'm not sure of the cost, and it may or may not be more cost effective than Blockx (who offer both a pure and mixed version), Holbein or Harding. Some other suppliers like Robert Doak might be able to give the same assurance if asked.
One artist has suggested using a pigment called terra bianca di Vicenza as substitute for zinc but there may be others...
Dr. Mecklenburg deserves a lot of gratitude for this study... it may save many paintings. We may have lost a lot of the knowledge of the "old masters", but we are also learning more in other ways. It is exciting to think what we are finding out through new technologies.
I forwarded the information to all my artist friends after my initial shock and received a reply from one:
"Thanks for the info. I am familiar with Dr Mecklenburg's research on zinc in paints. I also remember reading an Edward Hopper interview in which Hopper talks about zinc white as problematic. That interview is from 1959, but is prefaced by an earlier (1933?) statement of artistic purpose. Anyhow, that statement, and the whole interview are pretty interesting:
http://www.aaa.si.edu/collections/or...s/hopper59.htm "
Hopper may have had some sense of the problem with zinc, but like many of us didn't realize that zinc was in the titanium he was using.
all the best, j
Anon,
Could you check that Edward Hopper interview link? I couldn't get it to work.
Thanks,
Karin
Here you go:
http://www.aaa.si.edu/collections/oralhistories/transcripts/hopper59.htm
cheers, jp
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