Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-06-28

branch Of etching which is allied to the print
ing press, and which dates from about the year
1912.
In this work zinc, brass steel or iron may be
used, but for all high-class work copper is en-
ployed. Zinc does not lend itself tenderly, il
we may SO call it, to the etching process. be-
cause it almost impossible to eliminate the lead
which is always in the zinc of commerce. The
smallest particle of lead is at once eaten up by
the acid, and the result is a black hole. Brass,
being composition Of several metals, is
equally untrustworthy; and steel and iron are
out of the question, because of the superior
qualities of copper.
A copper plate of the first quality is cast to a
certain thickness in the rough. and is then
placed in n rolling machine, which t1attens the
whole casting into q nearly homogeneous mass.
Then it Is hammered, much in the same way
that gold beater hammers his gold, and the
result is plato IN which all the particles of
the metal are absolutely welded. When the
acid attacks the plate the action is uniform.
This is very important.
You are now supposed to have your copper
plate. II you are very particular and not
afraid of taking little trouble you will go over
it with willow charcoal and oil, and so make q
perfectly smooth and level surface. The
ground" is the next thing to consider. The
best authorities consider Bosses ground the
best. 1t is composed OF fifty grammes of very
pure white wax. thirty grammes of very pure
gum mastic and fifteen grammes OF asphaltum.
To make this mixture you must proceed with
some care. Get pan or shallow dish, fill it
with water and place it over slow fire. Into
this put pot and into the pot put the wax and
let it melt Then pound the gum ma site in a
mortar till it is reduced to very fine powder
and add it gradually to the wax. stirrin G with a
clean glass rod. When the mastic is quite
melted and thoroughly incorporated with the
wax add the asphaltum, which must have been
reduced previously to a fine powder. Add it
slowly stirring all the time, and see that the
amalgamation Is perfect. When the whole is a
unit, so to speak, pour the mixture into cold
water and when it hardens break it into bits
and put it into bottle. A wide-necked bottle
with glass stopper Is best
LAYING THE ETCHING anoUNp.
When ready to lay your etching ground, take
portion of the mixture and add oil of laven-
der, which will reduce it to paste of about the
thickness of ordinary printing ink. With
palette knife spread small quantity OF this on
a slab of clean plate glass. and with a dabber
or roller beat or roll it until it is evenly mixed.
dabber may be made by taking small guam
tity Of cotton wool or horse hair, rolled up into
a ball about the size of the fist. Cover this
with cotton cloth, and over all put piece of
black silk, sewing it firmly and leaving the ends
sticking up to serve as sort OF handle. The
roller Is more difficult to make, as 1t requires
skilled workman to draw tine leather over the
wooden cylinder SO that there shall be no
wrinkles. And when the edges of the leather
meet they must be beveled and cemented SO
that it may be, practically, one solid piece OF
leather.
Now dab or roll the plate with the etching
ground and see that it is evenly and thinly laid
upon the copper. 1t requires little ground to
resist the action Of the acid, and If the ground
In lumpy or uneven there will be trouble in
cutting through it to the copper to get uni
form set of lines The ground being laid you
must get rio of the oil of lavender, which may
be accomplished by holding the plate over a
spirit lamp.
Now cover the back of the plate with the
same etching ground, so that when it goes into
the acid bath the whole of the copper may be
protected. While the plate is still warm hold
it face downward over a smoking wax taper,
moving the plate in every direction until the
surface is evenly blackened, care being taken
that it is not burnt
now FOR THE DRAWING.
The plate is now ready III you are able to
make a good free-hand sketch you may pro-
ceed at once to draw on your copper. Ii, from
want of facility, you fear to attack that even
mass of black, you may sketch the picture on
bit of tracing paper and lay it face down on
your copper, aud, with soft and moderately
blunt pencil, go over the lines, which show
plainly through the transparent paper. This
will give you the design on the surface of the
etching ground family outlined. If you need
something more definite rub some red chalk
on bit of writing paper and lay it face down
on the copper, under the tracing paper, and
proceed as before. You will find on the plate
faint red outline of your design.
Now get two pieces of wood somewhat longer
than the plate and trife higher, and lay one
on each side OF the plate. Another piece of
wood is placed on these side pieces which gives
a rest for the hand when drawing. Remember
the hand must not touch the plate until the
acid has done its work; and right here let me
say that the utmost cleanliness must be OBJ
served in every stage of the process of etching.
and also with all the various materials. Dust
is a most serious damage if it gets into the
etching ground, on the plate. the dabber or
anything else used in the process.
cannot emphasize too strongly the impera-
tive need FOR absolute cleanliness in all the
stages of etchings, from the time the bare cop
per Is cleaned to the pulling of the trial proof
For amateur work the tools are very simple
thin steel wire set in wood, the size and
shape of lead pencil, may be bought of any
tool maker. You may make your own by whit
tling bit OF pine to the size Of lead pencil
cutting slight grove on one side, placing in
the grove an ordinary knitting needle and bind
ing 1t securely with thread. Sharpen the point
Oh an oil stone 10 get good cutting edge and
you are equipped. A burnisher and scraper
are also necessary, as you may have to tighten
certain parts.
IN THE BATH.
We will now assume that the drawing has
been cut through the etching ground to the
copper. Each line should now appear as a
bright yellovish red. Examine each line care
fully to see if the copper has been fully ex-
posed. II all seems right the plate is ready for
the acid bath. Mr.. +. &. Hamerton, u great
authority on etching, strongly recommends a
bath which Is known the Dutch mordant"
1t is composed Of chlorate of potash, 20
grammes. hydrochloric acid, 100 grammes and
water, $50 grammes. II this list of materials is
obtainable the manner Of compromising it is as
follows: First heat the water by putting bottle
containing II into pan also containing water
and keep 1t on the fire until the water In the
pan boiis. Now add the chlorate of potash and
| see that all the crystals are dissolved. Shake
| the bottle so that the various parts may be
| thoroughly mixed. Then add the hydrochloric
acid.
For ordinary work should advise equal
parts OF nitric acid and water. This bath is
very active and needs constant care, but you will
see that in every chemical process you must
conform to the requirements of science. You
may try experiments, but be certain OF the me-
dinms. Science, like the sun in photography,
only recOc nizea the voasihilitiea of hat