This has become the oil painter's holy grail: toxic, hard-to-find, expensive, and has special properties. Ensconced in art history as the older way to make lead white, as well as the actual lead white of the masters, Dutch Process or Stack Process Lead White is super-lead-white which is even harder to get than normal lead white.
With an appeal like this, who could resist? Besides, it has totally different handling. Normal lead white pigment is mass-manufactured and has a different particle shape and size. Stack Process lead white is made in a wild way involving sheets of metal, vinegar, closed sheds, months of wait time-- and wait for it-- manure, at least in some cases.
(In regard to lead white, Much more can be found on the entry for PW1).
