Lead White Oil Paintss
Rublev's lead whites are my preferred white oil paint whites for all of my paintings. Lead White #1 and Stack Process White Lead begin to set up in 6 to 8 hours, more or less, which suits my ways of painting perfectly. These create very durable paint films that should last for centuries. Lead White #2 is my favorite for painting skies, because it allows more working time to create the soft transitions of tones that make for compelling skies in a painting. The Stack Process White Lead is especially suited for painting faces in portraits, it being essentially the same kind of white used by Rembrandt in the 17th century.
I also appreciate the availability of a number of other paints that are not available from mainstream paint companies. Among them are Lead-tin Yellow, Naples Yellow, and several varies of siennas, all composed of the natural pigments that those names denote, rather than approximations composed of combinations of synthetic pigments and dyes whose lightfastnesses are inferior to the real thing.
These wonderful oil paints do not need mediums added to them in order to improve them in any way, in my experience. The need for mediums with some other brands is due to the too-thick consistency that is the result of stabilizers added to the paints by the manufacturers, which turn the paints into something like window putty that doesn't lend itself to good control under the brush. Thus painters feel the need to add mediums to overcome the stiffness caused by the stabilizers. Rublev oil paints have no stabilizers, so there is little or no need to add anything to them to achieve good control. These are the kinds of paint the Old Masters used. I'm a frequent buyer and constant user of Rublev oil paints.