KERAMIC STUDIO 
$9 
HINTS ON UNDER-GLAZE. 
[Sec May Number.] 
Chas. L. 1 'oik mar. 
'AINTING. — Under-glaze colors assume their 
proper tone only after glazing, but as the 
respective values of some colors remain 
nearly the same, and can be classified, the 
painting is not as difficult as it may appear at the first 
moment. 
It is important therefore to observe certain rules in choice 
of colors, for the respective plans of the decoration ; for in- 
stance, before commencing, one should decide on a scheme of 
treatment, and not deviate from this arrangement. In other 
words, classify those colors which will gain but slightly in in- 
tensity, and those which will grow dark, and some which will 
become very intense. The colors changing the least are 
Yellow, Matt Blue and Red T. 
In the second class we will place Dark Brown, Light 
Brown, Warm Green and Dark Blue or King's Blue and 
Maroon. 
Those colors which become very intense, and consequently 
difficult to control in their dry state are French Green, Black 
and Dark Blue or Mazarine Blue and Orange Strong. 
To illustrate the above, I will commence with a landscape 
treatment. 
For the sky and distance, use Matt Blue, Red T. and 
Yellow. These colors will not lose their respective values, or 
in other words, one will not gain more than the other in the 
glazing process, consequently produce no discordant notes 
in the distance and at the same time retain their air qualities. 
The only one of these colors that will change is Red T. which 
loses in intensity. 
To obtain a sunset effect, the red must be painted 
stronger, allowing forJts partial disappearance. Greys should 
be made of Matt Blue and Red T. adding a little white. For 
the 'middle ground use the same colors with the addition of 
Dark Brown, King's Blue and perhaps Maroon. Do not ex- 
pect to get a grey with thin Black, it will fire green. For the 
foreground, the Warm Green, Black, Claret Brown and Orange 
are the most suitable. As the French Green will gain a great 
deal in intensity after glazing, it must be used with a great 
deal of discretion. 
French Green becomes very intense when used heavy, 
whereas when used in a thin wash, that is reduced with gum 
Tragacanth, it becomes a very useful color. Be very careful 
not to use any French Green in the middle ground until the 
decoration is nearly finished, that is until you have done all 
possible with a green composed of Yellow and Matt or King's 
Blue. 
It is only by following these rules that a complete under- 
glaze landscape .with aerial quality can be produced. 
In marines the same rules must be observed. Never use 
pure greens in painting water, but compose your water tones 
with yellow and blue, adding a little black. If it is possible 
to introduce a pure note of green on a boat, figure or 
similar object with French Green, it will enhance the 
grey qualities of the water and so help the decorative color 
scheme. 
Flower decoration should also be painted very simply, 
although less precaution is necessary than with the previous 
two mentioned. 
I have named already the flowers most suitable for under- 
glaze. The best result is obtained in treating the background 
generally deep in tone. Leaves should be painted first with 
the composed green I have given in painting marines, and 
only retouched with thin pure green. Pure green can be used 
in the background at once, mingled with Claret Brown, Orange 
and Black. 
Do not paint shadows of flowers too strong, but always 
try to treat flowers as a light mass against a dark ground, and 
you will be certain to obtain a good result. Remember that 
you are making a decoration before everything else, and do 
not calculate to produce much detail. If you desire flowers 
with detail paint them in the over-glaze process. 
Figure decoration is the most difficult of all the branches 
in this style, as it requires the most interpretation. It is 
onl}' in the most simple treatments that success can be 
expected. 
In under-glaze painting the handling of the colors should 
be firm, not thin and not heavier than to give a clear tone of 
color. A strong outline treatment in finishing will help to 
give character. 
Keep separate water for colors and washing brushes. 
Water used for thinning colors should always be clean. 
When colors work dry or sandy more Gum Tragacanth is 
required. A little Gum Arabic helps to bind the colors, but 
the Tragacanth serves as a vehicle, that is, facilitates the 
handling or carrying the color from the brush to the clay 
surface. 
A glaze for under-glaze process can be bought fluxed for 
different degrees of heat. It may be on the lead basis, a 
borax glaze, or of an alkaline nature. Each glaze will produce 
a different result in intensity of color. 
The glaze may be laid on with a brush, mixing it with 
Gum Tragacanth water; it also can be applied with an atom- 
izer. Dipping a painted piece is very uncertain. If the 
painted surface is flat a fine sieve is very useful, but this re- 
quires more experience. For glazing with a brush, the follow- 
ing hints may be useful. Take about a tablespoon ful of glaze 
and grind on a clean slab to the consistency of cream and put 
in a saucer. When decoration is perfectly dry, take a broad 
camel's hair brush (about one inch) and lay on an even coat- 
ing of glaze with a light touch. Be careful not to disturb the 
painting. Commence on one end of the piece and work over 
towards the other, covering every part as you proceed. A 
surface less absorbent will require a thicker mixture than a 
more absorbent one. 
It is only by experience that you can perfect yourself in 
laying on the glaze. 
Should there be dead spots after firing, the piece can be 
reglazed and refired ; in this case, however, mix the glaze with 
water only. 
FIRING. 
The decoration is now ready for the firing, which is a very 
important part of the process. Some kilns are more suitable 
than others. It is important, however, to use one in which 
the least iron is exposed. The degree of heat in the kiln 
necessary for the firing depends on the amount of flux in the 
glaze. 
The regular English or French under-glaze colors in the 
market should be fired to at least deep orange red. A pure 
orange red or about 2,ooo° Fahrenheit produces the best re- 
sults, but I do not know of any of the portable kilns that 
would stand this heat. 
