Asphaltum, Bitumen or Whatever

[fechurch]

Thank you for correcting me, George. I was under the impression Silver White was modern white lead because Carlyle's Artist's Assistant describes it as "precipitated lead carbonate." Regardless of the manufacturing process, I imagine the distinguishing characteristics of this variety of lead white were a purer white color and lesser body due to differing proportions of lead hydroxide from the more common white lead. Of course I know the "fancy names" are misleading, but expect there was some difference in color/handling for artists to have used both normal white lead and the one labeled silver white.

[George O'Hanlon]

It may be that the blanc d'argent or silver white was produced by a precipitation process, but since this name was used to designate many different productions of lead white, we cannot be certain.

Church (1901) notes 'The blanc d'argent of the French is supposed to be lead carbonate free of any hydrate, but the great majority are nothing but flake white of good quality.'

Osborn (1845) states that silver white was supplied in the form of drops, 'that is, little cones,' adding that 'A Silver White has of late years been manufactured at the establishment at Clichy, near Paris... It is said to be fully equal, if not superior, to the Austrian' (called Krems white).

If the pigment was produced in Clichy, then it was produced by the stack process method. The principal difference between common forms of lead white and those of Krems and silver white is the purity of the lead metal used to make the pigment. The process used in Austria, did result in a different particle morphology, and may have been a brighter white than ordinary lead white.

[fechurch]

Thank you. I'm always interested in 19th century colors.

[George O'Hanlon]

We built a facility that replicates the manufacturing process used in Klagenfurt (the location of manufacturing for Kremsweiss in the 19th century), and we wil being producing a Krems or Cremnitiz white by late summer 2011.

[fechurch]

And I thought your lead whites couldn't get any better. Thanks, George!