You may recognize that the above painting is detail of the Dutch artist Johannes Vermeer's "Milkmaid" (circa 1658). The original hangs in the Rijksmuseum in Amsterdam, the Netherlands, which regards it as "one of the museum's finest attractions"
My copy is a class assignment by Danni Dawson, painted over the period of several weeks. We were learning the grisaille method of monochrome underpainting, which was used extensively by most Old Masters in the past. We did the underpainting with burnt sienna and ivory black paint; a thick layer of white paint went over the underpainting; then, finally, thin layers of glazes of other colors were laid on to bring out the glow.
If you mess up the underpainting, no matter what fancy glazing work you do, there isn't much you can do to rescue the mess. But over the beautifully-done underpainting, all you need is a small amount of pigments to finish off the painting. That is how the Old Masters maximized the effect of expensive pigments. I must say it is a tedious way of painting, but there is no denying the exquisite glow the glazed paintings have.