8o 
RERAMIC STUDIO 
a violet grey by the mixture of 
Nickel glaze lo 
Cobalt glaze 3 
Colorless glaze 87 
a blueish green by the mixture of 
Chrome glaze 30 
Cobalt glaze 3 
Colorless glaze 67 
a golden brown bj^ the mixture of 
Manganese glaze 50 
Iron glaze 50 
These few examples show what an artist fond of experi- 
menting may do with these glazes made each from^ one oxide, 
but which can be combined ad iafinitum. 
The gres colored glazes must be fired in an oxidising at- 
mosphere to keep the quality of their tones, 
Flammes or Flambes 
This name is given to glazes which derive their coloring 
power from copper and iron, and which during firing, are sub- 
mitted to the constantly changing influence of the flames which 
whirl in the kiln. After firing they present variable effects, 
according to the more or less oxidising or reducing action of the 
flames, also to the pyrochemical combinations which the 
various elements of these glazes produce together. It is easy 
to understand that at the high temperature at which these 
combinations are formed, it requires the greatest care to avoid 
the oxidising of a metal as sensitive as copper, which is turned 
green by an oxidising action lasting a few hours. Hence the 
unlimited variety of flammes. 
I have told in the article on firing how to obtain a re- 
ducing atmosphere at will. 
The red cuprous glaze is prepared in a special way because it 
contains substances which are soluble in water. The matters 
which compose it must be combined in the crucible. 
The following should be thoroughly mixed and fused: 
Pegmatite (feldspar) 1 08,0 1 
Quartyz sand of Fontainebleau 126,0 
Zinc oxide 15,5 {strictly 
Carbonate of baryum 36,0 j reducing 
Fused borax 45,0 
Dry carbonate of sodium 16,5 | 
After fusion, the glass thus obtained is pulverised and 
colored as follows: 
Ground glass 10,000 
Oxalate of copper i ,200 
Calcined tin oxide 1,100 
This new mixture is carefulty ground so as to form a 
homogeneous mass, and the glaze is applied, quite thick, on 
the raw ware, with the brush and gum tragacanth. 
Whatever the care given to the preparation of this erratic 
glaze and to its firing, it is difficult and very rare to obtain 
pieces identical in tone, even when they closely resemble each 
other. However Chaplet has shown me two flammes which 
were absolutely identical on their four faces, although each of 
these faces was of a different tone. I must add, however, that 
these two pieces were only 2\ inches high and had been fired 
side bj?- side in the same sagger. 
But if flammes can give a succession of deceptions, they 
also give a succession of unexpected and fascinating results. 
Reds of copper will develop on both bodies, gres and 
porcelain. I have obtained them on both, but flamme red 
porcelains possess a brilliancy and freshness which is given 
them by the underlying material and makes them superior 
to flannne red gres. 
Among flanmies are the celadons of iron. These are 
produced by the introduction into the glaze of I to 3% iron 
Paiit'l in kaolinic gres by Taxile Doat, purcha.sed by the French Government for 
the Mu?ee du Luxembourg. Subject : Venus. Figure and small flowers in white pate 
sur pate on green ground. Decoration of small squares in mac and bright yellow. 
Cartouche and columbines in mat pale blue speckled with rust. 
oxide. Just as for the reds of copper, a strictly reducing at- 
mosphere is necessary and saggers must have spaces free from 
lute (Fig. 81) to allow the flame free access into them. The 
greatest part of the old Chinese and Corean celadons were thus 
obtained with iron. These celadons are finer on gres than 
porcelain, especially when the glaze is calcareous. 
Here is the formula of flamme celadon of iron, which re- 
sembles the Corean celadon and may be seen on some of my 
gres vases: 
Sand 33,35 I 
Chalk 19,70 I 
Feldspar in flour 26,30 
Claj^ey kaolin 8,60 
Red ochre of Burgundy 12,00 ) 
Flowing Glazes 
The use of borax in flammes has led the Sevres chemists to 
study the combinations of this substance with other oxides and 
its influence upon their development. By superimposing a 
boracic glaze over a colored glaze, one obtains this curious 
series of marbled effects, the shade of which varies with the 
glazes used, while the greater fusibility of the boracic glaze 
provokes the flowing and sliding of both, so that they mix their 
colors in the most unexpected and harmonious way 
The use of this process of decoration requires much prac- 
tice in the disposition in spots or clouds of the boracic glaze over 
\ to be strongly 
fritted. 
