54 
RERAMIC STUDIO 
plasticity which is an advantage for the latter is the reverse for 
the former. A very plastic slip will be slow, long in setting and 
wet to handle. A certain amount of plasticity is necessary but 
not too much. The mixture in question is a compromise, it is 
plastic enough to work and free enough to cast. Slip is the 
better for age. A white clay on being stored in slip shape will 
assume a bluish color and often acquire a strong smell. This is 
no detriment, in fact a potter prefers his material in tliis con- 
dition. If an old whiskej^ barrel can be procured and filled 
with slip it will be an advantage. A good store is a great help. 
A stout stick for stirring should be provided, a pitcher or two, 
a flour sifter with the wheel taken out and a long handled 
dipper. After making and becoming somewhat aged the super- 
fluous water should be dipped or drawn off and the thickened 
mass thoroughly stirred. One of the pitchers is now filled, the 
slip being dipped up and poured through the flour sifter to arrest 
lumps. It wall probably be found somewhat frothy and the air 
bubbles should be worked out. This is done by pouring slowly 
fronT one pitcher to another, pouring carefully down the side so 
as to break the bubbles and avoid causing more. 
If the bubbles prove obstinate, as they sometimes will, a 
little of the slip should be poured into a bowl and thinned with 
water, then, with a badger softener or other large soft brush the 
whole interior of the mould is mopped with slip. The mould is 
now put together and tied with twine and the slip is poured 
carefully in at the top. It is filled to the brim and at once the 
slip is seen to settle down. This is caused by the absorption of 
water by the plaster. The mould is filled up again and again 
and then the edge may be examined to see what thickness of 
clay has accumulated. The thickness of a piece of pottery 
should be always proportioned to its size. When the proper 
thickness is reached the mould is carefullj^ lifted, be quite sure 
that the bottom is held firmly, and the contents poured back 
into the pitcher or barrel. It should be turned mouth down- 
ward for a w^hfle to drain and then the Hp of the vase, all round 
the spare edge, should be genth^ pushed away from the mould. 
This serves two purposes, it assits the vase in its separation 
from the mould and it informs the operator of the kind of re- 
lease he is to expect. Moulds and clays behave differently, 
some cling obstinately to each other, some part company with 
readiness. The first cast from a new mould is nearly always 
bad. The inner face of the mould always has some of the size 
upon it and this prcA'-ents a uniform absorption. It is therefore 
a common practice to make a rough filling, pourin^; slip in and 
out and opening the mould at once to remove the soft clay. 
This saves time but is a small test of courage for it appears to 
involve the loss of the first piece. When the mould, with the 
contained vase, has stood say ten minutes, bottom upwards, 
the bottom mould may be gently detached and laid aside. 
After a few ixdnutes more the halves may be gentty separated 
and the vase taken out. Extreme care is necessary at this 
stage. Cast clay is very tender, many times more tender than 
plastic clay, and must be handled very gently. The vase must 
be set on a dry bat and put aside to become hard. It requires 
some resolution to refrain from attempting to finish a soft piece 
but the endeavor must end in disaster. The work, positivelj^, 
must not be touched until it is perfectly dry. The exceptions 
to this rule are when the clays are to be changed in shape or 
painted with slip, or perforated. These are done while the 
piece is moist. When quite dry the spare piece may be cut 
off, the seams rubbed down and the whole finished. 
A few words here on the faults developed in casting. Pin- 
holes are caused by air bubbles and have already been men- 
tioned. If the cast cracks in the mould it may be because the 
body is not plastic enough or that the flint and feldspar are too 
coarse. In the former case add a little ball clay, in the latter 
endeavor to procure a finer brand of material or use a finer sieve 
through which to strain the slip. If the clay holds fast to the 
mould and will not be separated without damage the mould is 
probably too hard. This is governed by the amount of dry 
plaster added to the water when making the mould or, possibly, 
to the plaster being poured before it was ready. For casting 
moulds a pound of plaster to a pint of water is enough, for 
moulds used in pressing plastic clay this may be increased to 
one pound, six ounces to the pint. In pouring casting moulds 
the operation should be delayed as long as possible. Allow the 
plaster to thicken until it can only just be poured smoothly and 
the moulds will be "kind" and mellow. 
In burning cast ware it should be remembered that pottery 
made this w^ay shrinlfs considerably more and will stand a 
higher heat than pottery made by hand. 
STUDIO NOTES 
Miss E, E. Page, of Boston, Mass., went to Europe on 
June 19th for art study and travel. 
Air. Charles Volkmar is building three kilns at his Metuchen 
N. J. pottery, for different kinds of work. Besides his well 
known art pottery he expects to turn out artistic work in plastic 
tiles and enameled terra cotta. His son Leon Volkmar will 
work with him. 
Miss Emily Peacock will teach enameling on metal dur- 
ing the summer at the Guild of Arts and Crafts, East 23d 
Street, New York. 
TREATMENT FOR SWEET PEAS 
F.B. Aulich 
FIRST painting: Paint in the background with Albert 
Yellow, Yellow Green, Yellow Brown and Oliv-e Green in 
the dark parts, wipe out the fights with a No. 5 pointed brush, 
shade the light flowers with Grey for White Roses, the others 
with Aulich Rose and American Beauty color, the leaves with 
Yeflow Green. 
For the second and last painting use the same colors over 
again, pad the entire surface so that aU colors blend, and then 
finish them with a thin pointed brush which we call a stemmer, 
used for stems and the fine lines. 
