011r - - - - - Painting esmail d’azur in oil
This is a secret that is hardly known to common painters. Some take the most delicate they can & grind it with ceruse, which binds it, and next prick with an awl in several places the area they want to paint with azur d’esmail, such that the oil enters & leaks in, & ne does not cause the azure, which in itself is heavy, to run. Others lay the panel flat & put down the azure on it, which is also done à destrempe. The main thing is to grind it well on marble, and before that, to have washed it thoroughly. Some grind it with thoroughly with an egg yolk & then wash it in five or six waters and lay it on not with a painceau, which would be too soft, but with a broisse thoroughly softened & crimped, & laying it on thickly as if one were putting it down with a trowel; settling down it evens out and flattens. I have experienced that grinding azur d’esmail with egg yolk & next washing it in several waters is good. However, it loses a little of its vividness in the grinding of it. I have also washed it in several waters &, when it had settled a little, I removed the water, still q blue, with a sponge and squeezed it into another vessel thus where it settled, & from the residue I had the ash, flower and subtlest part of the azure without grinding it, which is the best, for in the grinding of it, it loses some of its tint. Those who make it in Germany compound it like enamel, in large pieces which they pestle, & pass through several sieves & wash.
To make azures beautiful, they wash or soak them in a rock water, as they call it; it is a water distilled from mines where azure or vert d’azur is found, which distills naturally through the veins of the mountain or is distilled through an alembic par from mineral stones of azure or copper.
Azure ash are only good for landscapes because they die in oil. Only true azure holds on. Azur d’esmail cannot be worked if it is too coarse. Try it, therefore, on the fingernail or the oil palette. If it happens to be sandy, do not grind it except with the egg yolk or, better yet, wash it in clear water & with a sponge remove the colored water after it starts to go to the bottom, and in this manner you will extract the very delicate flower, which will be easy to work with.