PHOTOGRAPHS ON ENAMEL
THERE are several methods by which photographs may be reproduced upon
enamel. However, since they are rather difficult, we will explain only
one method, and for the other processes will refer the student to Dr.
Paul Liesegang’s treatise on photographing on enamel, porcelain, and
glass, which is printed in German.
In the first place only the best quality of mirror glass should be used
for the plates, as it is essential that they should be perfectly smooth
and without blemishes. The glass should then be cut the same size as the
negative plate which is to be used later. The glass plate must be made
perfectly clean, which is best done by placing it in a mild sulphuric
acid bath for about ten minutes and then washing it well with clean
water. It should be dried with a clean cloth or tissue paper, after
which it may be wrapped in clean dry tissue paper and kept in a dry
place until needed.
[Illustration:
FIG. 10. POLISHING.
]
Out of the many receipts for preparing the sensitive solution, we will
give only the two most generally found satisfactory. These are as
follows:
(1) Dissolve one-half ounce of ammonium bichromate in five ounces of
clean water. In another glass dissolve one ounce of grape sugar and one
ounce of gum arabic in five ounces of clean water. When the solutions
are completely dissolved, they should be mixed together, stirred
considerably, and filtered several times.
(2) Dissolve one-half ounce of Le Page’s best fish glue and two ounces
of grape sugar in five ounces of clean water. In another glass dissolve
one-half ounce of ammonium bichromate in five ounces of clean water.
When both are perfectly dissolved, pour the two solutions together, and
stir them well, after which the mixture should be filtered several
times.
These solutions should be prepared in the dark room and should not be
kept more than a day or two, as both light and time will destroy their
power. They should be kept in the dark room in a glass-stoppered bottle.
The sensitive solution, however it may have been made, should be poured
over the clean, dry glass plate already described, as soon as possible
after it is made. This is done in exactly the same manner that
photographers prepare wet plates. The waste solution running off the
glass plate should be filtered and saved as it may be used again. This
pouring must be done in the dark room and dust must be carefully
avoided. The wet plates should now be dried on an iron frame covered
with paper and heated from underneath by a small gas or alcohol lamp.
They should not be heated hotter than the hand can comfortably bear.
When they are perfectly dry, they should be left in the dark room in a
dry, warm place, free from dust and should be used the same day.
The next step is to place the negative that is to be reproduced in a
copying frame with the glass side out. It should be perfectly clean and
free from dust. The sensitive plate is then put in the frame with the
sensitive side towards the negative. Any friction between the plates
must be avoided. This, of course, is done in the dark room. The plates
are now exposed in the sunlight from half a minute to a minute. If
exposed in the shade it will take from five to ten minutes. If the
weather is very damp it is advisable to use a previously warmed
sensitive plate and negative for exposure to the light, since damp
weather injures the sensitiveness of the plate. Also it is well to avoid
any sudden change of temperature during the exposure. In the winter it
is best to make the exposure in a warm room having about the same
temperature as the dark room.
After the exposure is finished, the copying frame should be carried to
the dark room, where the next operation must take place. First, the
exposed sensitive plate should be taken carefully out of the copying
frame and placed on a piece of paper with the sensitive side upward. The
picture will not as yet be discernible upon it. Now place a quantity of
black or brown dry enamel paint on the plate and gently scatter this
powder over it by means of a soft, clean, dry brush, which should be
kept for this purpose only. Then brush the enamel powder back into its
bottle. It is very essential that no dust shall get into it. After five
or ten minutes repeat the powdering and so on two or three times until
the picture is clearly developed.
If the sensitive plate has been underexposed, the picture will develop
rather quickly at the first powdering. This will generally give blurred
reproductions, and it is scarcely worth while to bother longer with that
plate. The only thing to do is to make another exposure. With a well
exposed plate, the picture should develop slowly, that is, not before
the second or third powdering. If the weather has been exceedingly dry,
it is advisable to breathe gently on the exposed sensitive plate before
beginning the powdering. If, on the other hand, the weather has been
damp, the plate should be warmed slightly before powdering.
[Illustration:
FIG. 11. PICKLE POT OR DIP BASKET.
]
When the picture shows clearly, brush all the surplus powder carefully
from the plate, which is now ready to be treated with collodion. Add
about twenty drops of castor oil to a pint of 2 per cent collodion
solution and mix it thoroughly. This mixture, which must be free from
air bubbles, should now be poured over the powdered plate. The waste
collodion which runs off the plate is contaminated by traces of the
enamel paint and cannot be used again. After the collodion has hardened,
cut around the edges of the plate with a knife and then place the plate
with the collodion side upward in a dish containing a weak solution of
caustic potash (half an ounce of caustic potash dissolved in a quart of
water). This solution will remove all the chromium which has served its
purpose. Leave the plate in this solution until the first appearing
yellow coloring has disappeared, and then place it with the collodion
side upwards in a basin with slowly running water, which will in about
an hour wash away all the chromium and potassium salts. The plate should
then be placed in a dish of clean water to which a few drops of nitric
acid have been added, not more than enough, however, to give the water a
slight sour taste. The plate may remain over night in this solution
without harm to the picture, although a couple of minutes will be found
entirely sufficient if one is in a hurry.
Next, the plate should be placed in a large basin of clean water with
the collodion side downwards. If the collodion film has previously been
cut properly around the edges, it will soon separate from the plate,
which may be removed, leaving the collodion film floating in the water.
Meanwhile, the enameled metal plate, which has been prepared exactly the
same as is done for enamel painting, should be cleaned with a soda
solution to free it from all grease. It should now be placed upon a wire
support and carefully brought under the floating film which can be
deposited gently on the enameled surface by means of a soft brush. The
plate should then be taken slowly out of the water and the overlapping
parts of the film should be turned under the edges of the plate, after
which it should be put on a piece of white blotting paper to dry.
If any air bubbles appear under the film, they should be brushed very
gently with a soft, wet brush towards the edge of the plate, where they
will do no harm. If this does not prove successful, the bubbles may be
opened with a needle, after which the air may be pressed out with a wad
of soft paper.
When the plate with the collodion film on it is perfectly dry, the
collodion should be removed by placing the plate in a dish of
concentrated sulphuric acid. Within a few minutes the collodion will
entirely dissolve. When this has taken place, a brownish ring will
appear around the plate, whereupon the plate should be removed at once
and put in a large basin of clean water. Finally, it should be submerged
in a weak solution of ammonia (one ounce of ammonia to a quart of
water), which will neutralize the last traces of the acid, after which
it should be left on a piece of blotting paper to dry.
The picture may now be retouched just as photographers retouch ordinary
photographs, only the same enamel paint should be used that was used in
the powdering process. After the retouching, the plate may be fired in a
muffle, just as is an ordinary enamel painting, and then covered with a
layer of fondant. The finished photograph may, however, be painted with
enamel paints if the enameler desires to make a colored photograph.
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WHERE ENAMELERS’ SUPPLIES CAN BE OBTAINED
ENAMELS, HOWARD M. CHAPIN, 84 Keene St., Providence.
ENAMEL PAINTS, WADSWORTH, HOWLAND CO., Boston.
FURNACES, SIMPLEX TOOL AND SUPPLY CO., Boston.
MUFFLES, SIMPLEX TOOL AND SUPPLY CO., Boston.
GRINDING MACHINES, ABBE ENGINEERING CO., New York.
CARBORUNDUM, CARBORUNDUM CO., Niagara Falls.
WAX BOTTLES, BAKER & ADAMSON CO., Easton, Pa.
ACIDS, PUMICE, ETC., GEO. L. CLAFLIN CO., Providence.
TILES, BECKLEY PERFORATING CO., Garwood, N.J.
FELT, BROWN BROS. CO., Providence.
PAILLONS, HOWARD M. CHAPIN, 84 Keene St., Providence.
DECALCOMANIA FILMS, MALDEN CHINA CO., Malden,
Mass.
MORTARS AND CHEMICAL GLASSWARE, GEO. L. CLAFLIN CO., Providence.
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● Transcriber’s Notes:
○ Missing or obscured punctuation was silently corrected.
○ Typographical errors were silently corrected.
○ Inconsistent spelling and hyphenation were made consistent only
when a predominant form was found in this book.
○ Text that was in italics is enclosed by underscores (_italics_).
○ The use of a caret (^) before a letter, or letters, shows that the
following letter was intended to be a superscript, as in S^t
Bartholomew or 10^{th} Century. .it The use of an underscore (_)
before a letter, or letters, show that the following letter was
intended to be a subscript, as in HNO_{3} (nitric acid).
○ If there is more than one letter in a superscript or subscript
they are enclosed in brackets—{}.
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