Considering that titanium (oil paint) forms a weaker film than lead, and it’s been in use for around 100 years, is anyone aware of any conservation issues arising from its use yet?
Also, I’m interested in mitigating the weakness of titanium with the addition of lead. Does anyone know if there have been any stress tests done with different proportions of lead mixed with titaniun?
Ron Francis
Thanks George.
I know there is no data to answer my question, but I was particularly wondering if the effect of different combinations of lead and titanium was linear or some other curve.
Ron Francis
Thanks Brian, you echo my thoughts.
I would love to see some testing, but I doubt that I would see any useful results in my lifetime. 😉
Interestingly, According to Sarah Sands, Mecklenburg still hopes that some proportion of zinc would be beneficial.
Although, I think that was possibly a couple of years ago now.
Ron Francis
Studies of twentieth century paintings containing titanium dioxide have found examples of titanium dioxide that have degraded, but these were the anatase form of titanium dioxide mostly from the first half and middle of the century. Most artist materials companies today use the rutile form of titanium dioxide, which does not appear to suffer the same issues.
I am not aware of any studies that show benefits of using specific proportions of lead white in oil paint, but some beleive that as little as 20% may be sufficient to impart its benefits in oil painting.
There are a couple of truisms here. Titanium dioxide, even rutile, makes a weak paint film on its own. This is why manufacturers always added a certain proportion of more reactive zinc white to their titanium whites. This turned out to be a problem as well. Second, lead white makes the strongest, most stable paint film of the three common whites. Third, there has just not been enough testing, at least no “published” testing that I am aware of, to show whether the beneficial affects of adding lead white to other colors are linear or on a curve.
