2 4 8 
KERAMIC STUDIO 
\0 
W^? 
Hispano-Moresque Tiles in the Metropolitan Museum. By courtesy of the Museum. 
METALLIC DEPOSITS ON GLAZES 
Louis Franchet 
FROM tradition and from rare manuscripts, we learn that 
ten centuries ago, at a time when the application of 
metals over enamels was unknown, ancient potters ob- 
tained by reduction deposits of copper and silver on the 
glaze which covered their wares. Modern ceramists have 
attempted to imitate these lustres by simpler methods, in 
the oxidizing atmosphere of their muffles, but the results 
have been disappointing and have only made the question 
of glazes and glasses with iridescent reflections still more 
confused. 
The uncertainty which has always existed in regard to 
these metallic deposits is due to the fact that those obtained 
by reduction have been considered similar to those obtained 
in an oxidizing atmosphere. They are two entirely differ- 
ent kinds of deposit, however, and the difference in their 
properties enables us to establish a marked distinction be- 
tween them. 
The time of the discovery of metallic deposits over a 
vitrified substance is uncertain ; it seems to date back from 
the foundation of the first potteries established by the 
Arabs in the East about the period of their great conquests. 
The oldest examples of faience covered with iridescent 
enamels date from about the IX. century and are claimed 
by Orientalists to be of Arabian manufacture. Persia has 
transmitted to us some remarkable iridescent pieces, but 
none seems to be anterior to the Mussulman invasion, and 
all bear the characteristics^ Arabic art. 
It is only at the beginning of the XIV. century that 
this manufacture developed to any extent, when the Moors, 
according to Baron Davillier 1 established in Malaga their 
first faience factories; the iridescent wares were then, under 
the name of golden ware, 2 exported all over the world, and 
potteries multiplied in Spain. This fabrication was prosper- 
ous until the end of the XV. century, when Ferdiand V., 
king of Aragon, delivered the peninsula from Mussulman 
domination and it disappeared almost entirely when in 1610 
Phillip III expelled the Moors who were still residing in 
Spanish provinces. Spain, however, has never entirely 
ceased producing faience with metallic reflections, but the 
few potters who have succeeded to the Moors have never 
given to their manufacture the importance which it had 
under the Mussulmans. 
In the XV. century, Italy, which had always been an 
important market for the golden ware of Spain, undertook 
its production. This attempt would probably have failed 
if a Sienna potter, Galgano di Belforte, had not gone to 
Valencia and succeeded in obtaining the secret of the Mores- 
que process. The Italians even improved upon this pro- 
cess, and Giorgio Andreoli has left us majolicas with metal- 
lic deposits, the splendor of which has never been sur- 
passed. 
France also had once factories of iridescent wares; 
one in Narbonne, about which little is recorded, and one in 
Poitiers much better known. 3 At the end of the XIV. cen- 
tury, the Duke of Berry secured from Valencia a Moorish 
potter, and established in Poitiers kilns and the necessary 
installation for the manufacture of ceramic tiles with metal- 
lic iridescence. 
In 1882, an Italian potter introduced among the 
potteries of Golfe Juan and Vallauris the use of a decora- 
tion with metallic deposits. The method there employed, 
which we will study later on, is the same which was used 
in the Middle Ages, and the same tradition is observed by 
1. Davillier — Histoire des Faiences Hispano-Mauresques a reflets metalliques, 
Paris, 1861. 
2. In Spanish, obra dorada, in French, oeuvres dories. 
3. lj. Magne — Le Palais de Justice de Poitiers, Carreaux emailles du 
XV erne Siecle (La Ceramique, T. VII, p. 157). 
