252 
KERAMIC STUDIO 
deposits, he simply used copper oxide in a muffle containing 
faience heated to a red heat. 
I have tried the old processes by following strictly the 
instructions which accompany them, and I have obtained 
deposits absolutely identical to those found on Renascence 
faience. I have also sought to determine the blue and 
green tones which are found there occasionally, also the 
golden, yellow and brown tones which were obtained at 
Deruta toward 1530. My experiments convince me that 
the blues and greens are due to the metallic mixtures, while 
colors shading from golden to dark brown are due to the 
more or less prolonged action of reducing gases. 
I have composed the following formulas : 
No. i No. 2 
Copper carbonate 30 Copper carbonate 28 
Red ochre 70 
No. 3 
Silver carbonate 3 
Subnitrate of bismuth . 1 2 
Red ochre 85 
No. 5 
Copper sulphide 20 
Tin protoxide 25 
Red ochre 55 
No. 7 
Silver sulphide 5 
Red ochre 95 
Silver carbonate 
Red ochre 70 
No. 4 
Copper oxalate 5 
Silver carbonate 1 
Subnitrate of bismuth . . 10 
Red ochre 84 
No. 6 
Copper carbonate 95 
Silver carbonate 5 
No. 8 
Copper sulphide 2 
Silver sulphide 1 
Subnitrate of bismuth . . 17 
Red ochre 80 
These different combinations were applied over enamels 
of various compositions vitrifying at 990 C. (Seger cone 
08), then heated to 650 C. (Seger cone 020), the third fir- 
ing mentioned in the Moresque process, and submitted 
there to an intense reduction. Formulas Nos. 1, 2 and 5 
gave metallic iridescent effects similar to those obtained 
with the old Arabic and Italian formulas. Nos. 3, 4 and 
8 gave indigo blue deposits, sometimes green with No. 3, or 
a mixture of blue and green with Nos. 4 and 8. No. 7 gave 
brilliant tones, pale yellow, golden and brown (similar to 
the effects obtained at Deruta), and No. 6 a brass yellow 
tone. 
The influence of bismuth oxide is evident; its presence 
determines an intense blue shading into green in silver com- 
binations, while the latter, if used alone, produce yellow or 
brown deposits. It is then very probable that the Italians 
used this metal which is mentioned for the first time by 
Agricola in 1529 and was considered by some authors as an 
water bottle with the arms of the Duke of Segorbia, about 1450-1470. 
Courtesy "of the Metropolitan Museum of Art. 
impure silver. It is as such probably that it was tried and 
frequently employed later on by Francesco Xanto Avelli di 
Rovigo (i 530-1 550), the last artist who used in his studio 
in Urbino, the ruby red and golden effect. The violet and 
purple lustres on his ware show us that he had thoroughly 
mastered all the processes of the manufacture, even more 
so perhaps than Giorgio Andreoli whose fame is much 
greater. 
The different tones obtained with silver combinations 
are due to the action of reducing gases, as I have studied it 
by modifying somewhat the Moresque process. Instead of 
applying the metallic mixtures over the glaze, I have in- 
corporated them into the glaze itself, thus making the ob- 
servation of phenomena much easier, because the fusing of 
the ochre mixture with the underlying glaze was not then to 
be feared, while in the ordinary process this fusing occurs 
every time that the temperature of the muffle is allowed to 
rise during reduction. 
(TO BE CONTINUED) 
STUDIO NOTES 
Mrs. Vance-Phillips is back from Los Angeles and has 
resumed her classes in her New York studio, 647 Madison 
Avenue. 
Miss Laura Overly has resumed her classes in porcelain 
decoration in her New York studio, 27 West 26th street. 
BOWL DESIGN IN BLUE GREYS— LOUISA JORDAN 
OF NEWCOMB COLLEGE 
BOWL DESIGN^ IN CAFE AU LAIT AND OLIVE GREEN 
—NANCY BEYER 
