Lustre is an antique decoration technique
which, through application of a metallic salt and a clay diluted
with wine vinegar, (and special type of firing) produce chromatic
iridescent effects of; golds, ruby reds, and silver. Of Middle-eastern
origin, lustre is greatly diffused in the art of Arabic
ceramics, reaching about the second half of the 15th century
in Deruta and in few other Italian centers.It is unknown how,
but thanks to the bartering with Spain and in particular with
the island of Majorca, (from which came the name “Majorica”
then “Majolica”) that the Renaissance made lustre
ceramic famous.
Lustre is applied with a paint brush on
the surface of completed objects. They are then glazed and
fired, and usually suitable spaces are left by the painter
at the time of decoration, like in this fine inspiring Renaissance
plate. They are then prepared, and fired a third time.
This deals with low temperature firing, of
about 620°C, and is produced in a decreasing atmosphere,
meaning that introducing smoking substances (such as; wood,
broom, horse nails, sugar etc,.) may inhibit the oxidation (reduction)
of metals which cause the special effects of pigment and refraction
in recognition of the luster. After the firing and a slow
cooling, the plate is recleaned.
Clay residues are removed and the remaining
smoke on the surface. This leads way to the shine and sparkle
of the lustre.