252 
ItERAMIC STUDIO 
Polychrome Delft, XVII Century 
The property of the Metropolitan Museum, New York 
THE DECORATION OF RAW TIN GLAZES 
Louis Franchet 
THE progress made in modern ceramics, as a result of 
chemical and mechanical discoveries, has given us 
new products, as regards both the composition of bodies 
and the coloring matters and their use. 
Has art progressed in a direct ratio with these technical 
improvements? I do not think so. True ceramic art, such 
as was transmitted to us by the marvelous artists of the 
East, does not exist any more. It has been gradually re- 
placed by industry which aims at quantity rather than 
quality. 
However, it is a mistake to claim that we have no 
artists capable of executing such fine decorations as have 
been made in old Persia, or of reproducing the delicate 
compositions of the Italian Renaissance. We still have 
clever ceramic artists, but conditions of modern life prevent 
them from displaying and developing their talent. In our 
times a ceramic fabrication means an intensive production, 
and, as the sale must be rapid, it must be done at low prices. 
Art becomes impossible. On the other hand, ceramists 
who are true artists and would like to produce fine examples 
of craftsmanship, find a great difficulty in selling their 
works which are not understood, the great majority of the 
public being interested only in low prices. 
The result is that most of the so-called art ceramics 
have nothing artistic but the name which has been given 
them by fashionable publications, or which they owe to 
cleverly presented advertisements. Among the many prod- 
ucts which are now sold in Europe under the name of "grand 
feu gres," how many really belong to art? Very few indeed, 
as even these high fire ceramics must be sold cheap. 
In the beginning of the XIX Century the fabrication of 
porcelain, then new in Europe, gave a blow to the produc- 
tion of stanniferous faiences which, from the XIII to the 
XVIII Centuries, had been the glory of Spain, Holland, 
France and Italy. When, at the end of the XIX Century, 
modern processes of decorating were applied to gres, we 
seemed to entirely forget the splendid decorations which 
were formerly obtained by painting over the raw tin glazes. 
It is this interesting method of decoration which I 
will explain to readers of Keramic Studio. I will first 
give a rapid historical sketch, and then speak of the technical 
processes. 
The Eastern artists of the old time knew the use of an 
"envelope," that is, the application of a clayey material 
over another clay. The object of the white envelope, the 
most frequently used, was to hide the natural color of the 
clay which constituted the body of the ceramic piece. 
When the Persians discovered, at a very remote date 
which we do not exactly know, that tin had the property 
of making glazes opaque, they created the stanniferous 
glaze which during many centuries was the basis of ceramic 
decoration. 
Tin glazes were introduced into Europe in the VII 
Century by the Arabs, who founded in Spain the famous 
factories of Malaga, Manisses, Valencia, Toledo, Morviedro, 
Barcelona, Muncia, etc., which had their greatest develop- 
ment in the XV and XVI Centuries ; in France, the factories 
of Narbonne and Poitiers (XIV Century) . This Arab fabrica- 
tion, in France as well as in Spain, is mostly known by its 
faiences with metallic reflections (lustres). 
From Spain tin glazes went to Italy, which glories in 
the products of Gubbio, Deruta, Pesaro, Caffagiolo, Faenza, 
Castel-Durante, Urbino, etc. 
Finally the Italian potters brought their art to France 
in the first half of the XVI Century, and the famous factories 
of Rouen, Nevers, Moustiers and others show us that the 
artists of that great period had a higher conception of ce- 
ramic art than we have to-day. 
We will now study the colors and processes which were 
used by these old potters whose masterpieces we admire 
to-day in our Museums. These processes which are claimed 
by some to be lost secrets, are little known simply because 
ceramists affect to neglect or even to despise the knowledge 
of the chemical constitution of the colors which they use. 
And I will remark that these great decorators of old owed 
the splendid handling of colors which we admire in their 
works to the fact that they knew perfectly their composi- 
tion. Most of them prepared their own colors. It is true 
that in this time of intensive production we cannot ask our 
artists to spare the time for such drudgery, but they ought 
at least to realize the importance of knowing the constitu- 
tion of the materials which they use. 
Pottery, Italian, 1500-1520— Gubbio Plate 
The property of the Metropolitan Museum, New York 
