Sequence viewing > Index - Alternative Photo Emulsions - Resource - ©
Lloyd Godman
Alternative
Photographic Processes - (Hand
made photographic -emulsions and processes)
Van
Dyke Brown Recipe & Process
Coating
the sensitive emulsion:
Read
safety instructions
Step
2.
In
very subdued or a yellow or red safe light, coat the surface of the
paper with the solution. Use of a clean brush without metallic ferrule
is recommended.
Make
sure that the emulsion is stirred before use.
(Some
recipes suggest coating the paper twice allowing for drying between
coats, but I have found that if you are careful in the application one
coat seems to work fine).
Additional coating information:
During
storage the iron and silver can tend to separate out at different levels
in the liquid.
Some
photographers recommend storing each of the stock solutions separately,
but as the mixture matures giving a deeper richer tone with age, it
is recommended to leave for at least a day in a combined state. With
combined solutions, make sure you gently agitate the solution to mix
it before use; failure to do so can result in uneven coating of silver
and iron in various areas.
While
this can produce some interesting effects, they may not be those you
desired.
Use
gloves and other protective equipment as the mixture and stain skin.
Applying
the emulsion too thickly can create a situation where the top layer
of the emulsion becomes dark on exposure and blocks the light from reaching
the lower layer, so that in the developing stage both layers wash away.
Experiment
with emulsion thickness - a thin coat can produce surprisingly delicate
tones. Thinning the emulsion down slightly can assist with this.
Experiment
with application techniques, foam brushes can be used, foam rollers
can give and even coating.
Abbreviations
can be incorporated as part of the work.
Be
aware that some papers are fragile and may need taped down to a board
for coating and processing, also some papers may need sizing to stop
the emulsion soaking into the fibres of the paper.
Drying
the emulsion
Step 3.
Dry
the paper in darkness or subdued light and keep in darkness until use.
If you are coating a great number of sheets a drying rack is ideal,
but be careful that there is no wet emulsion or contaminants on the
rack where you place the paper.
A
hair dryer can be used to speed the drying up. Some manuals recommend
using the sensitised paper with in 12 hrs. I once forgot about some
paper in this state and used it after about 3 weeks without any great
difference. This did not seem to effect the sensitivity: The only effect
was that the tonal quality might have been a little softer.
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