Wow! Writing about and using Wallace Seymour paints has been a real eye opener, really there is no one making such rare and interesting paints and being made by practicing painters truly shows in the pigment choices and feel of the paint.
Genuine smalt made from blue glass or 'Cobalt glass' has been used as a pigment for a very long time in fact it has been found in works from ancient Egypt from 2700 BC, it is now very hard to find (the raw pigment is pictured opposite).
The blue comes from the Cobalt element and helps speed drying, this version is sourced from Stoke-on-Trent in England.
In masstone hue it is similar to a mid-ultramarine blue, it stands up well to white and produces almost sky blues in tints. It has a slightly granular feel due to the glass particles if they are ground too finely they lose their colour.
It also has a depth not present in other blues I suspect provided by the irregular refraction of light from and through the glass.
This is special and different, well worth experimenting with, I certainly will be.
Pigment - Smalt/Cobalt Glass
Opacity - Semi-Transparent
Binder - Linseed Oil