Robert Gamblin, from Gamblin Artists Colors, has just released an in-depth article about the different white pigments that artists use. It deals with everything from a pigment’s tone to its flexibility! Although I don’t purchase a lot of materials personally, Robert’s work in this area continues to inspire me; I hope you enjoy the article.
I’ve been experimenting with creating a shell white from some mussel shells I found along the Conestogo River a couple of years back. With work beginning on some local-colour plant paintings, I again find myself in need a local white pigment …
Shell White could be the answer: It has a long history of use in some cultures; provides a durable inert pigment; and, represents a material found within many diverse places. The single drawback that I’m aware of, is that it only remains opaque when unvarnished … But this won’t be a detriment in my current application.
The creation of shell white is straight forward enough: Collect your shells; then clean them; then crush them. In my case many of the shells I found has been abandoned for many years, and there wasn’t much organic matter left (I did end up having to grind off the outer part of the shell in order to remove this brown outer layer). This done, it crushed up easily and after being ground created a fine pigment.
But, this first batch is not as white as I had hoped—It has a grey hue that looks white enough when I apply it to a painted area, but on a white background it is decidedly off-white. I don’t know if this was caused by my process or is indicative of the material itself … but I think there’s potential here. I’ve ordered a little bit of Kremer’s Gofun Shirayuki pigment to see what a professionally prepared sample is like; and I’ll be trying another batch for myself soon.
While I really love the idea of following the historic method for making flake white, I have also decided to try and create this pigment using some of the newer methods developed within the last century.
I’ve come to realize that in making flake white I am creating a pigment by taking my ore through a number of small steps. In short, the ore is being slowly dissolved using acetic acid fumes and then reacting with the carbon dioxide released from the manure (the heat helps quicken the process). You can imagine that there is an awful lot of different ways to make this happen beyond the traditional Dutch stack method …
My first help in trying to create a modern process came from Reiner. In an old plumbing book he owns, he found a recipe combining glacial acetic acid with hydrogen peroxide that claimed it would dissolve old plumbing solder. Putting it to the test, it did just that; creating a lot of bubbling and over roughly a day completely liquefied my ore.
Step one complete!
I have been eagerly waiting to see what will happen in my attempt to create flake white and I am happy to write that the process of changing my ore into a carbonate is going well. As you can see the little medallions have quickly begun to develop a white crust!