A non-lead white from Rublev.
I like this very much, it has the 'length' of Rublev paints meaning it produces a long brushstroke, rather than a buttery, tight paint which produces a short brushstroke.
It is slightly warmer than a standard Titanium white and a less powerful tinter, meaning you have much greater control over your tints, as we all know pure Titanium white can be hard to manage.
Finally it is semi-opaque, which again in contrast to a normal Titanium provides an opportunity to get away from the 'flat opaqueness' of Titanium white, also giving it a better relationship with earth pigments.
Pigment - PW6 & PW22
Vehicle - Linseed Oil
Opacity - Semi-Opaque
Tint Power - Medium
Part of my lockdown painting time has been spent experimenting with Rublev whites. I find this Mixing White very useful. It's not as brutal as Titanium White which I avoid. James is quite right. it enables greater control when mixing tints.