14 
KERAMIC STUDIO 
MARMALADE JAR— MIRIAM BOONE 
BEGINNERS' CORNER 
JESSIE M. BARD ------ Page Editor 
Dickinson Seminary, Williamsport, Pa. 
ACID ETCHING 
Treating Design of Marmalade Jar by Miriam Boone 
ONLY white china can be used for acid etching. Divide 
the jar in three equal parts and trace the design on and 
outline with India ink according to previous instructions. 
The bands can be drawn in with either a Keramic gauge or 
with the use of a banding wheel. All parts of the design that 
is not to be lowered or etched must be covered with a resist 
for the acid. Turpentine Asphaltum is used for this purpose 
and can be bought at a hardware store or where painters' sup- 
plies are sold. 
This work is not hard if the pupil will exercise a little 
care and judgment in working but some people make great 
labor of it. The Asphaltum becomes gummy in a short time 
so it is best to take out just a little with the end of a palette 
knife, about a teaspoonful. Use a china slant to work it up 
in or a small saucer would answer. A great many people get 
it on the handle of the palette knife and of the brush and on 
their hands and thus get everything sticky, making hard work 
of it and themselves uncomfortable, but this is not necessary. 
Keep the asphaltum about the consistency of enamels so it 
flows easily from the brush, thin it with turpentine when it 
becomes too stiff. Use a No. 1 or 2 Winsor and Newton red 
sable brush. Keep the asphaltum on the tip of the brush 
only and flow it on just as enamels are flowed out. It should 
be applied heavy or the acid will eat through it. Light brown 
places are thin places and are to be avoided. Work for straight 
edges as ragged edges spoil the effect of the design. Cover all 
of the design and the bands with the asphaltum, leaving the 
background white, then cover the remaining surface of the 
jar leaving a white space about a sixteenth of an inch all 
around the design and bands. Every thing must be covered 
that is not to be etched, for the fumes of the acid will dull the 
glaze. The acid can be applied as soon as the asphaltum is 
dry. The acid used is Hydrofluoric. This is one of the strong- 
est acids made and great care should be taken in the use of it. 
Have a bottle of ammonia convenient to use in case you get 
any on you. If one is inclined to be careless one had better 
not use the acid, though there is no danger if one will take 
ordinary precautions. Take a brush handle or a small stick 
and wrap a small piece of cotton tightly on the end of it, 
make a swab, dip this in the acid and then apply it to the white 
parts of the china left exposed, this is done with a rolling motion 
of the stick, if it is rubbed on the asphaltum will be rubbed off. 
Make another application when the china looks dry; it usually 
takes about an hour to absorb it. Length of time to etch 
depends on the hardness of the china, it usually takes about 
six or more applications of the acid. The depth can be tested 
by taking a pen knife and scraping along one of the edges. 
When it is dry enough hold the article under running- 
water to remove the acid then place it in boiling water until 
the asphaltum becomes soft enough so it can be scraped off 
