ROCKLAND COLLOID CORP,in their kit "Tintype Parlor" says:
"Tintypes, also known as ferrotypes, are last century's -instant-
photographs.Historically,-wet plate- tintypes, containing silver halide
in collodion, came first.They were obsolete by -dry plate-tintypes which
used gelatin instead of flammable collodion.Dry-plate tintypes were
coated on steel that was painted black and sometimes on black paper or
cardboard.(the-tin- in tintypes comes from the similarity of the metal to
the steel used in socalled -tin- cans.).The Tyntipe Parlor produces
authentic dry-plate tintypes.
Tintypes are an optical ilusion that is based on the same principle as
when you view an underrexposed or thin black-and -white negative by
reflected light while it is held against a dark background:The negative
image seems to become positive.With tintypes,the exposed silver image is
actually lighter than the unexposed areas of the black background,giving
the appearance of a normal positive print.
Because tintypes eliminate the negative used in conventional prints,they
are -first generation- prints and produce an image of exterme sharpness
and resolution.Other characteristics of tintypes are that subjects are
optically reversed so that left becomes right and vice-versa, and colors
reproduce differently from modern black-and-white emulsions:Reds appear
to be black and blues,white.The highlights of tintypes are not pure white
as in conventional prints, but a distinctive yellow-brown:These effects
are all part of the distintive appearance and appeal of dry-plate
tintypes.
Now it's time to try your hand at tintyping.An old box or view camera
with a bulb or time exposure setting is excellent.A tripod is
necessary.If you have an exposure meter , place a blue acetate film over
the photocell to measure only the blue content of the ambient light- the
only color that tintypes are sensitive to.Dress your models in old
clothes from the attic,and enjoy operating your own tintype parlor."
Here in Spain, bibliography on the topic doesn't exist.
Regards,
Manuel Estebanez