The first step is to place your emulsion coated paper and negative under glass.
This keeps the two in contact during exposure and allows for a detailed exposure
of the negative. Often people will use a custom built contact printing frame
made from a glass photo frame with a door on the backside.
I somehow ended up
with two large 16x16 inch and 1/2 inch thick glass from a garage sale. I tape
the glass pieces together with as a hinge so they fold open like a book. I use a
large paper office clip to clamp the sheets of glass together during exposure.
An inkjet negative or objects used to cast shadows like leaves or feathers
A glass printing frame or glass sheets to keep the negative or objects flat against the print during exposure.
Getting Ready
>> First you will need your
prepared sheet of paper coated with emulsion, dried and
ready. You will also need your transparency printed and enough time allowed
for the ink to have dried.
>> In a dimly lit room, (a single lamp is perfectly
fine) take your negative and place it over your coated paper with the ink
side in contact with the emulsion. If your paper is curled a bit after
drying, just bend it gently as flat as you can get it.
>> Then you use masking tape and tape down the corners to
hold the negative in place.
>> Finally, place the paper and negative under glass in a
contact printing frame, to keep them firmly placed against one another.
I
have two sheets of furniture glass I found at a garage sale and clamp them
with a black office paper binder clip. If you are feeling experimental,
don't bother with the glass. The places where the negative and emulsion are
out of contact will blur slightly is all.
You are
now ready for Exposure!
Exposure Times
Before I had my own Ultraviolet light source, I would expose using the sun as
most beginners would. Typically, if memory serves me correctly, my exposures
ranged from 3-5 minutes in the hot summer Texas sun. Rarely, I might
go as high as 7 minutes with my exposure if a cloud happened to block the sun
momentarily, or if it was later in the afternoon when the sun is lower in the
sky. Determining gum Bichromate exposure in the sunlight is mostly guesswork
based on experience.
When I first printed in the sun, I would always coat two sheets of paper with
emulsion, and use one sheet as a test print to guide me, and the other as
the actual print.
Exposing in the Sun:
The sun works at exposing prints best during mid-day in the hours when the sun
is high in the sky. Clear days also are best since you don't have to worry about
passing clouds or hazy dust. Here in Texas during the summer...we unfortunately have plenty
of those days. Those HIGH UV days they warn you
about on the weather are also great for sun exposure. You might get a print to
expose in 2 minutes! If you plan on exposing a lot of prints in the sun, it
might be a wise idea to invest in some sun block so you don't expose yourself as
well!
Dust and gasses of the atmosphere scatter higher wavelengths of light and allow
longer wavelengths to pass through. It is similar to being able to hear long
bass wavelengths of music or muffled talking through walls, yet not being able
to hear high pitched sounds. When the sun sets, its light is passing through
miles and miles more air then it is during the mid day hours, and all that air
scatters the ultraviolet and blue wavelengths of light in all directions. The
redder longer wavelengths of light still make their way directly to you. This is
why the sun appears redder during sunrise and sunset, why the sky is blue, and
why it is best to expose your prints between 10am and 2pm.
>> First I coat 2 sheets of paper with the same batch of
Emulsion and let them dry. I designate one sheet as the test print and one
as the real print on the
backside. Set the real print aside in a
dark place for the moment
>> place your negative and test print under glass as shown above
>> You will need to use a piece of cardboard or some other
completely opaque material to block the sunlight from exposing the print. Go
outside and face your print and glass at the sun, either laying it down or
leaning it on a wall to angle it correctly.
Make sure it is steady and still beneath the cardboard
until you are ready to expose. It is best to have your print
perpendicular to the sunlight, or as close as possible.
Sorry, Illustrations coming soon!
I
rarely print using the sun anymore.
>> In 1 minute intervals, or 30 second intervals, move the cardboard about an inch
or two across the print. This will expose strips of the print in specifically timed
increments.
>> Cover the print up with cardboard again and bring it back
inside to develop it normally in water.
>> When the test print is finished with development, use your
judgment to determine the best exposure time for your image.
>> Now, Get your real print out of it's dark hiding place and expose it under negative and glass in the
sun using the exposure time you just determined with your test print. Develop it
normally in water.
Once the test print and real print are dry, you can
easily re-coat them for a second gum layer and repeat this process.
>> Place your dry coated paper and negative under glass as
shown above.
>> Slide it under the exposure unit. Set your exposure
time** on a cooking timer (or just use your watch). Flip the exposure
unit on and the lights will flicker a second or so as they warm up.
Promptly
start your timer.
**Your best exposure time will first need to
be determined by making either a test print as outlined in Exposing in the Sun above, or by making a few
prints at different exposure times and judging for yourself what looks best.
If you are using custom
negatives, you will have a range of working exposure times to choose from when
printing, and
it is your experience, judgment, and intentions which will determine which
exposure time to use. For more, see Using Custom
Negatives
>> When the time is up, flip off the exposure unit. Remove
your print from the negative and glass because it's ready for development!
