142 
GME HE decoration of pottery by means of col- 
= : = hess ored clays is capable of so much variety 
and yields such easy harmonies in color 
as to immediately commend itself to the 
worker in the studio. From time to time 
new methods of application have been 
found, the faience of Haviland, Rock- 
wood pottery, Moorcroft’s Florian and the charming crea- 
tions in pate-sur-pate by Solon and others, which have been 
hailed as something new, but the prototype of them all is 
the old slip painting of the Romans and of the medieval 
English potter. 
The condition of the clay piece to be decorated is most 
important. It should be just hard enough to enable you 
to handle it carefully without putting it out of shape. If 
used any harder than this the colored slips used in its 
decoration will peel off in the firing. It is essential to suc- 
cess to keep it in this condition until completely finished. 
This may be done by wrapping in damp cloths when not 
in use, or better by keeping it in a ‘“‘damp box.” ‘This can 
easily be constructed with very little trouble or expense 
by taking a box, driving in on both bottom and sides small 
nails or tinned tacks, leaving the heads projecting. Cover 
both bottom and sides with plaster of Paris, from one to 
one and a half inches thick accord- 
ing to size of box, for which the 
projecting nails form an anchor- 
age. Treat the cover in the same 
way and as soon as the plaster is 
set your box is ready for use and 
needs only an occasional sprink- 
ling with water to keep the plas- 
ter moist. 
The colored slips are prepared 
by mixing certain proportions of 
metallic oxides or underglaze 
colors with white clay, and must 
shrink during the firing in equal 
ratio with the body. The first 
requisite is a white base, which can 
be compounded as follows: 
BatleG@layes omen oe 33) parts 
GhinamClay (22. 22 281% parts 
ality th or eat 14 parts 
Cornish Stone’ --.-- 194 parts 
Beldspar .:. fas 5 pats 
100 parts 
This will mature at cone 1, as 
low a heat as is desirable to use 
to insure the ware holding water. 
When this has been prepared and 
lawned, dry it out on plaster bats 
AMERICAN HOMES AND GARDENS 
HANDICRAF TSMAN 
Conducted by A. Russell Bond 
Home-Made Pottery—Il] 
By W. P. Jervis 
Illustrations by E. M. Harlow 
Suggestion for a flower pot, tobacco jar, and a 
candlestick 
or in molds, so that it can be accurately weighed. Before 
trying to decorate any pieces it is best to make trials of 
the colors you intend using, so that the effect of both the 
glaze and the firing on them may be accurately judged. 
In preparing colored slips, first grind the colorant in a 
stone mortar and add it in the proportions given to the 
white clay, and stir thoroughly so as to obtain an intimate 
mix. Pass through a 120 mesh lawn and any residue re- 
maining on the lawn must be again ground in the mortar 
so that the whole will pass through the lawn. Leave it 
to settle, until after pouring off the water you have a slip 
of about the consistency of cream, and it is then ready 
for use. 
Coloring matter is added in the following proportions: 
1. Dark blue ...15 parts white clay, 1 part oxide of cobalt 
2. Peacock blue ..25 parts white clay, 1 part oxide of cobalt 
3. Light blue ...35 parts white clay, 1 part oxide of cobalt 
The cobalt cannot be too finely ground, as otherwise it 
will show in flecks of darker color, occasionally not an 
objection for grounds. The only remedy is to grind and 
lawn again. These three blues can all be improved by 
slightly reducing the quantity of cobalt and about doubling 
the difference with underglaze peacock and mat blue, ac- 
cording to tint required. No. 1, for 
instance, is considerably improved 
by adding green and mat blue as 
follows: 
4. Dark blue, 25 parts white, 1% 
parts oxide of cobalt, ™% part 
French green, % part mat blue. 
Greens can be formed from 
either oxide of copper vor 
chrome: 
5. Chrome green, 7%4 parts white 
clay, I part oxide of chrome. 
6. Blue green, 8 parts white clay, 
34 part oxide’ of chremeye 
part oxide of cobalt. 
7. Pearl green, 20 parts white 
clay, ™% part oxide of chrome, 
l4 part peacock blue, 4 part 
mat blue. 
8. Copper green, 20 parts white 
clay, 1%4 part oxide of copper. 
Oxide of chrome cannot be 
mixed with brown, yellow or or- 
ange, and any attempt to do so will 
result in failure. 
The brush, also, must be Kept 
perfectly clean. 
g. Black, 15 parts white clay, 1 
part underglaze black. 
