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Paul and I first refined the use of PnP paper-originally designed to create
printed circuit boards-to meet the artistic needs of metalsmiths, jewelers,
and enamelists (see Glass on Metal, Volume 15, No.3, August 1996). With
results similar to photo etching, but without the expense and more complex
procedures, the heat transfer method using PnP has revolutionized the
world of artistic etching. Now, the procedure is not only used throughout
the USA, but also in many other parts of the world.
However, throughout the years, while teaching numerous workshops in
this technique, I have been asked this question consistently: "Can one
use photographs?" Originally, my response had been that only black
and white line drawings were appropriate. Black lines will perform like
a resist and will not etch, while white registers "clean" and will etch
out. Unlike printmakers, who can create a range of gray tones on paper,
the metalsmith traditionally etches away an area in the metal or leaves
it intact. In other words, although a stippled or irregular area in metal
can be achieved, metal usually is totally etched out in a given area,
or it is not. For enamelists working in champlev?, it is especially important
to have "clean", etched out areas (unless one is doing experimental or
unconventional work) in which to inlay the enamel.
Nonetheless, the constant queries set me to thinking-could the photographic
process somehow be adapted to this method? The use of photography, especially
ones that capture texture and patterns, could add a whole new dimension
to etched metal and enamel work.
The first challenge was how to deal with the gray tones prevalent in
all photography. Randomly, a few photographs were Xeroxed, transferred
to PnP paper, heat transferred to metal, and subsequently etched. The
results were very erratic. As suspected, the pure black and white areas
transferred and etched beautifully. The gray tones, however, either translated
as slightly imperfect black areas (mostly unetched but with "pinholes")
or wildly imperfect stippled areas (partially and very irregularly etched
patches).
Some of the etched results were not uninteresting, but there was no
sense of control. For example, a partially etched section (from a gray
tone in a photograph) might contain an interesting random pattern, while
another partially etched section simply would look messy and blotchy-like
a result of sloppy technique! It made sense at this point to consider
some "refinement" of the Xeroxed photographs, just as I had
previously done with simple black and white line drawings. First, it seemed
important to use high contrast black and white photographs, when available.
This selection would emphasize the pure blacks and whites and cut down
on the tonal quality of the photograph. (It should be noted that color
photographs could be used, but a lot more "refinement" work on the xeroxes
would be needed to "clean them up".) Also, photographs with too many small,
unclear details were eliminated. Photocopies of the originals were made,
with judicious use of the "darker/lighter" control on the photocopy machine
to ensure the best quality reproduction. Some photographs were enlarged
somewhat in order to clarify the design and details.
Next, the black fine point magic markers and white-out pens were used
for "refinement" of the Xeroxed photographs. Black areas were made blacker
, white areas were "cleaned up" (same process as with the line drawings)
and artistic judgment was used to alter the gray areas creatively. Some
grays that were distracting were either totally whited-out or blacked
in. Other areas were worked into a more controlled pattern and some were
left alone, to be etched randomly when erratic results would be an asset.
At this point, the "improved" photo/Xerox was transferred to the PnP
and subsequently to the metal (again, see Glass on Metal? , Vol. 15, No.3,
Aug. 1996) and then etched. This time, the results were impressive, but
one result had not been anticipated. All the negative (i.e.) black areas
in the original photo/Xerox were now positive (unetched, appearing "light")
in the metal, while all the positive (i.e. white) areas in the photo/Xerox
were negative (etched away, appearing "dark") in the metal. The explanation
for this occurrence is that any area in the transfer registering as black
will not be etched; in other words, the black acts as an acid resist.
In many cases, this reversal is not important and sometimes even an interesting
variation on the original, but in other instances, it is disturbing. For
example, a photograph of a white building with darkened windows would
etch out as a recessed (etched-out/"dark") building with raised (unetched/
"light") windows.
The solution to this dilemma is to reverse the tones in the original
photograph, either by having a copy center create a reverse negative or
altering a scanned-in photo image on the computer. A reverse negative
of the aforementioned building would now present a dark building with
light windows. However, when etched in the metal, the image would appear
as in the original photo.
Please note that after the reverse negative is created, it too must
be "refined" as previously described. The end results of all these adjustments
are extremely satisfactory, although there are some variations and/or
simplifications from the original photographs due to the necessary "refinement"
process.

Another application in creating artistic images to etch with PnP paper
involves enlargement of drawings.
Usually I create my designs within a relatively small format (a 6" or
8" square or circle). But often I want to have a much larger piece as
the end result. In this case, after creating the original drawing, I will
enlarge it on a copy machine several times until I obtain the desired
size. Sometimes I have to divide the original into small "grids" and enlarge
each of these "grids" separately, if the copy machine I am using cannot
accommodate enlarged versions of the original past a certain point. It
is very important to enlarge each segment the same percentage or they
will not match up later!
In any case, once the drawing is the desired size-either in a single
piece or in segments pieced together-the black lines are blackened further
(they usually have lightened up considerably in the enlargement process)
and the white areas are "cleaned up". At this point "fills" may be inserted
into selected areas, or these may be inserted before enlarging; it depends
on the size and effect desired from the "fill".

The enlarged drawing next must be transferred to the PnP paper. If one
is using standard size (8-1/2" x 11") PnP paper, the enlargement must
be cut up into sections (either grid-like or free-form) and each section
(or possibly a couple of sections, depending on size) Xeroxed onto the
PnP blue paper. There is now anew larger size PnP blue paper (11" x 17")
and, if the enlarged design fits into this size, the entire design can
be Xeroxed in one piece onto it. Of course, the copy machine must also
accommodate both the larger size drawing and the larger size PnP. Next,
the image is transferred to the appropriate size metal and etched out.
If the piece has been divided into segments, these will be reassembled
after the etching (and enameling) is done.
A final note: always, when doing any kind of etching, it is absolutely
essential to refer to a reputable etching manual, both for good results
and for safety procedures, including proper acid disposal (ferric chloride
is used with PnP). Etching instructions must always be followed with care!
With this in mind, the artist should obtain beautiful results in a safe
and effective manner.
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